feat(stm32mp1-fdts): add support for STM32MP13 DK board

This stm32mp135f-dk board embeds a STM32MP135F SoC (900MHz / crypto
capabilities) and following peripherals: STPMIC (power delivery), 512MB
DDR3L memory, SDcard, dual RMII Ethernet, display H7, RPI connector,
wifi/BT murata combo, USBOTG/STM32G0/TypeC, STMIPID02/CSI OV5640.
Add board DT file taken from kernel.
Add fw-config files for this new board.

Change-Id: I7cce1f8eb39815d7d1df79311bd7ad41061524b8
Signed-off-by: Yann Gautier <yann.gautier@st.com>