doc: release-notes-4.0: Release notes cleanup

* Deprecated ``EARLY``, ``APPLICATION`` and ``SMP`` init levels can no longer be

  used for devices.

* Removed deprecated net_pkt functions.

Deprecated in this release

==========================

* The :ref:`kscan_api` subsystem has been marked as deprecated.

* Deprecated the TinyCrypt shim driver ``CONFIG_CRYPTO_TINYCRYPT_SHIM``.

* :ref:`native_posix<native_posix>` has been deprecated in favour of

  :ref:`native_sim<native_sim>`.

* ``include/zephyr/net/buf.h`` is deprecated in favor of

  ``include/zephyr/net_buf.h>``. The old header will be removed in future releases

  and its usage should be avoided.

* Deprecated the :c:func:`net_buf_put` and :c:func:`net_buf_get` API functions.

Architectures

*************

* Made these changes in other SoC series:

  * NXP S32Z270: Added support for the new silicon cut version 2.0. Note that the previous

    versions (1.0 and 1.1) are no longer supported.

  * NXP s32k3: fixed RAM retention issue

  * NXP s32k1: obtain system clock frequency from Devicetree

    versions (1.0 and 1.1) are no longer supported.

      * RW61x: increased main stack size to avoid stack overflows when running BLE

      * RW612: enabled SCTIMER

  * NXP IMXRT: Fixed flexspi boot issue caused by am erroneous relocation of the Flash Configuration Block

  * NXP IMXRT: Fixed flexspi boot issue caused by an erroneous relocation of the Flash Configuration Block

    of Kconfig defaults being sourced

  * NXP RT11xx: enabled FlexIO

  * NXP IMXRT116x: Fixed bus clocking to align with the settings of the MCUXpresso SDK

* Made these board changes:

  * :ref:`native_posix<native_posix>` has been deprecated in favour of

    :ref:`native_sim<native_sim>`.

  * The nrf54l15bsim target now includes models of the AAR, CCM and ECB peripherals, and many

    other improvements.

  * Support for Google Kukui EC board (``google_kukui``) has been dropped.

  * STM32: Deprecated MCO configuration via Kconfig in favour of setting it through Devicetree.

    See ``samples/boards/stm32/mco`` sample.

    See ``samples/boards/st/mco`` sample.

  * STM32: STM32CubeProgrammer is now the default runner on all STMicroelectronics STM32 boards.

  * Removed the ``nrf54l15pdk`` board, use :ref:`nrf54l15dk_nrf54l15` instead.

  * PHYTEC: ``mimx8mp_phyboard_pollux`` has been renamed to :ref:`phyboard_pollux<phyboard_pollux>`,

* Added :rst:dir:`zephyr:code-sample-category` directive to describe and group code samples in the

  documentation.

* Added a link to the source code of the driver matching a binding's compatible string (when one can

  be found in the Zephyr tree) to the :ref:`dt-bindings` documentation.

  be found in the Zephyr tree) to the :ref:`Devicetree bindings <devicetree_binding_index>` documentation.

* Added a button to all code sample README pages allowing to directly browse the sample's source

  code on GitHub.

* Moved Zephyr C API documentation out of main documentation. API references now feature a rich

  * Added initial support for Renesas RA8 AGT counter driver (:dtcompatible:`renesas,ra-agt`)

  * Added driver for Analog Devices MAX32 SoC series (:dtcompatible:`adi,max32-counter`).

  * Updated the NXP counter_mcux_lptmr driver to support multiple instances of the lptmr

    peripheral.

* Crypto

  * Added support for STM32L4 AES.

  * Deprecated the TinyCrypt shim driver ``CONFIG_CRYPTO_TINYCRYPT_SHIM``.

* DAC

  * DAC API now supports specifying channel path as internal. Support has been added in STM32 drivers.

  * Updated the NXP counter_mcux_lptmr driver to support multiple instances of the lptmr

    peripheral.

  * Updated the initialization of clocks for the NXP LPTMR driver

  * Converted the NXP S32 System Timer Module driver to native Zephyr code

  * Converted NXP S32 Software Watchdog Timer driver to native Zephyr code

    * Added Würth Elektronik HIDS-2525020210002

      :dtcompatible:`we,wsen-hids-2525020210002` humidity sensor driver.

    * Added general samples for triggers

    * Added driver for NXP's fxls8974 accelerometer

* Serial

  * Fixed compilation issues with networking and SystemView Tracing enabled.

  * Removed redundant DHCPv4 code from telnet sample.

  * Fixed build warnings in Echo Client sample with IPv6 disabled.

  * Removed deprecated net_pkt functions.

  * Extended network tracing support and added documentation page

    (:ref:`network_tracing`).

  * Moved network buffers implementation out of net subsystem into lib directory

    and renamed public header to :zephyr_file:`include/zephyr/net_buf.h`.

  * Deprecated the :c:func:`net_buf_put` and :c:func:`net_buf_get` API functions.

  * Removed ``wpansub`` sample.

* MQTT:

* Together with the deprecation of :ref:`native_posix<native_posix>`, many tests which were

  explicitly run in native_posix now run in :ref:`native_sim<native_sim>` instead.

  native_posix as a platform remains tested though.

* Added documentation (readme) for the erase_blocks flash test

* Extended the tests of counter_basic_api with a testcase for counters wihtout alarms

* Excluded NXP RW612 based boards from the WiFi test suite, as these boards require binary blobs

  be downloaded in order to build as expected

* Extended the tests of counter_basic_api with a testcase for counters without alarms

* Added support for testing SDMMC devices to the fatfs API test

* Extended net/vlan to add IPv6 prefix config to each vlan-iface

* Enhanced the camera fixture test by adding a color bar to enable automation

* Fixed floating point logging issue in the video driver sample code

* Added a number crunching (maths such as FFT, echo cancellation) sample using optimized an

* Added a number crunching (maths such as FFT, echo cancellation) sample using an optimized

  library for the NXP ADSP board

* Tailored the SPI_LOOPBACK test to the limitations of NXP Kinetis MCU's

* Enabled the video sample to run video capture (samples/drivers/video)