ext/hal: Introduce STM32Cube SDK for STM32F4xx family

With this commit we provide header and HAL/LL files for all STM32F4
SoCs (V1.13.0).
Using STM32Cube provides generic access to all families, maximizes
code reuse across different STM32 families and helps taking benefit
of a mature SDK.

Origin: STM32Cube
URL: http://www.st.com/content/st_com/en/products/embedded-software/mcus-embedded-software/stm32-embedded-software/stm32cube-embedded-software/stm32cubef4.html


Purpose: Introduction of STM32F4xx STM32Cube definitions and
	 Abstraction Layers
Maintained-by: External

Original STM32Cube tree structure has been modified to a minimum
structure for a better fit into Zephyr. hal is split into 2 parts:
-driver: initially Drivers/STM32F4xx_HAL_Driver, contains HAL and LL
-soc: initially Drivers/CMSIS/Device/ST/STM32F4xx, contains stm32f4xx
socs header files

Change-Id: I34ad6b711273ea27ceb2a07073499b153f37e044
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>