arm64: dts: rockchip: Add Anbernic RG351M

arm64: dts: rockchip: Add Anbernic RG351M

This device is a clone of Odroid Go Advance, with added PWM motor, internal
gamepad connected on USB instead of just having it be on GPIO + ADC, and
missing battery shunt resistor.
Due to missing shunt resistor and lack of a workaround in rk817_charger
driver rk817_charger is not enabled in dts.

There's also an LED on GPIO 77(I *guess* PB5 on &gpio2),
that is controlled in a weird way:

- It is set to red by setting output value to 1
- Set to green by setting output value to 0
- Set to yellow by setting gpio direction to input

I have no idea how to describe that in DTS, without adding a custom
driver, for now it's just left out.

Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com>
Link: https://lore.kernel.org/r/20221117215954.4114202-6-maccraft123mc@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>