boards: nordic: Add initial support for nRF54L10 with TF-M

This adds the nrf54l15dk/nrf54l10/cpuapp/ns board variant to
Zephyr. It allows to build applications for this target.

This is an initial support for the non secure target which allows
building and running tfm_ipc and config_build.

This is NOT full support of the non secure target in upstream
Zephyr.

There are important limitations, such as:
  - The hardware Crypto accelerator is not supported and thus the non
    secur target is NOT secure for production applications in upstream
    Zephyr.
  - The BL2 is not supported, so no DFU is supported with this support

Most of the code changes here are taken from nRF Connect SDK
in order to avoid having noups there.

Signed-off-by: Georgios Vasilakis <georgios.vasilakis@nordicsemi.no>