dt-bindings: arm: rockchip: Add ROCK 5 ITX board

Add devicetree binding for the ROCK 5 ITX board, built around the rk3588.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20240704153815.837392-2-heiko@sntech.de

Author: mmind

Documentation/devicetree/bindings/arm/rockchip.yaml

@@ -816,6 +816,11 @@ properties:
           - const: radxa,rock-3c
           - const: rockchip,rk3566
 
+      - description: Radxa ROCK 5 ITX
+        items:
+          - const: radxa,rock-5-itx
+          - const: rockchip,rk3588
+
       - description: Radxa ROCK 5A
         items:
           - const: radxa,rock-5a