arm64: dts: rockchip: Add Anbernic RG-DS

arm64: dts: rockchip: Add Anbernic RG-DS

Add device tree for the Anbernic RG-DS, based on the Rockchip RK3568.
All hardware is currently working except for the accelerometer, the
speaker output, and one of the two battery gauges. A bug in the
Rockchip VOP2 driver is currently causing the device to pause for 30
seconds at boot and is being investigated.

The Anbernic RG-DS includes the following (supported) hardware:
 - 2 640x480 DSI display screens with touch.
 - 21 buttons.
 - 2 Analog joysticks.
 - 3 LEDs (red and green LED share the same housing).
 - 32GB eMMC, 1 SDMMC slot.
 - RTL8821CS WiFi/Bluetooth combo
 - 1 USB 2.0 port in host mode, 1 USB 2.0 port in peripheral mode.
 - 3.5mm headphone jack with play button support.
 - 4000mAH battery

The following hardware has incomplete driver support and is not yet
working:
 - An Invensense icm42607p accelerometer.
 - Two Awinic aw87391 speaker amplifiers.
 - A Cellwise cw2015 battery monitor, which appears to conflict with
   the rk817 charger driver at the moment.

Co-developed-by: Alexander Weinzerl <aweinzerl13@yahoo.com>
Signed-off-by: Alexander Weinzerl <aweinzerl13@yahoo.com>
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Link: https://patch.msgid.link/20260113195721.151205-7-macroalpha82@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>