dt-bindings: arm: rockchip: Add Anbernic RG-Arc

Add the Anbernic RG-Arc S and RG-Arc D devices, and consolidate
all Anbernic RK3566 based devices under a single description.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240123212111.202146-3-macroalpha82@gmail.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>