dt-bindings: arm: rockchip: Add Toybrick TB-RK3588X

Add devicetree binding for Toybrick TB-RK3588X board from Rockchip Toybrick.
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Weizhao Ouyang <weizhao.ouyang@arm.com>
Signed-off-by: Elon Zhang <zhangzj@rock-chips.com>
Link: https://lore.kernel.org/r/20240221022902.751528-2-zhangzj@rock-chips.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

Documentation/devicetree/bindings/arm/rockchip.yaml

@@ -881,6 +881,11 @@ properties:
           - const: rockchip,rv1108-evb
           - const: rockchip,rv1108
 
+      - description: Rockchip Toybrick TB-RK3588X board
+        items:
+          - const: rockchip,rk3588-toybrick-x0
+          - const: rockchip,rk3588
+
       - description: Theobroma Systems PX30-uQ7 with Haikou baseboard
         items:
           - const: tsd,px30-ringneck-haikou