dt-bindings: arm: rockchip: Add Powkiddy RK2023

The Powkiddy RK2023 is a handheld gaming device made by Powkiddy and
powered by the Rockchip RK3566 SoC. Group the Powkiddy RK3566 based
devices together as they are both extremely similar.
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20231117202536.1387815-5-macroalpha82@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

Documentation/devicetree/bindings/arm/rockchip.yaml

@@ -674,9 +674,11 @@ properties:
           - const: pine64,soquartz
           - const: rockchip,rk3566
 
-      - description: Powkiddy RGB30
+      - description: Powkiddy RK3566 Handheld Gaming Console
         items:
-          - const: powkiddy,rgb30
+          - enum:
+              - powkiddy,rgb30
+              - powkiddy,rk2023
           - const: rockchip,rk3566
 
       - description: Radxa Compute Module 3(CM3)