arm64: dts: ti: Add support for Variscite VAR-SOM-AM62P

arm64: dts: ti: Add support for Variscite VAR-SOM-AM62P

Add device tree support for the Variscite VAR-SOM-AM62P system on module.
This SOM is designed to be used with various carrier boards.

The module includes:
- AM62P Sitara MPU processor
- Up to 8GB of DDR4-3733 memory
- eMMC storage memory
- PS6522430 chip as a Power Management Integrated circuit (PMIC)
- Integrated 10/100/1000 Mbps Ethernet Transceiver Analog Devices ADIN1300
- Resistive touch panel interface controller TI TSC2046
- I2C interfaces

Only SOM-specific peripherals are enabled by default. Carrier board
specific interfaces are left disabled to be enabled in the respective
carrier board device trees.

Link: https://www.variscite.it/product/system-on-module-som/cortex-a53-krait/var-som-am62p-ti-sitara-am62px/
Signed-off-by: Stefano Radaelli <stefano.radaelli21@gmail.com>
Reviewed-by: Judith Mendez <jm@ti.com>
Link: https://patch.msgid.link/20250909213749.28098-3-stefano.radaelli21@gmail.com
Signed-off-by: Nishanth Menon <nm@ti.com>