board: stm32: Add Engicam MicroGEA STM32MP1 MicroDev 2.0 7" OF

7" OF is a capacitive touch 7" Open Frame panel solutions with
- 7" AUO B101AW03 LVDS panel
- EDT, FT5526 Touch

MicroGEA STM32MP1 is a STM32MP157A based Micro SoM.

MicroDev 2.0 is a general purpose miniature carrier board with CAN,
LTE and LVDS panel interfaces.

MicroGEA STM32MP1 needs to mount on top of MicroDev 2.0 board with
pluged 7" OF for creating complete MicroGEA STM32MP1 MicroDev 2.0
7" Open Frame Solution board.

Linux dts commit details:

commit <1d278204cbaa> ("ARM: dts: stm32: Add Engicam MicroGEA STM32MP1
MicroDev 2.0 7" OF")

Add support for it.

Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>