dt-bindings: arm: rockchip: Add Powkiddy RGB10MAX3

The Powkiddy RGB10MAX3 is a handheld gaming device made by Powkiddy and
powered by the Rockchip RK3566 SoC.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240212184950.52210-7-macroalpha82@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>