dt-bindings: soc: rockchip: add clock to RK3588 VO grf

The RK3588 VO GRF needs a clock. This adds the clock to the allowed
properties, makes it mandatory for the RK3588 VO grf and disallows it
for any other Rockchip grf.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20240213163609.44930-2-sebastian.reichel@collabora.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Documentation/devicetree/bindings/soc/rockchip/grf.yaml

@@ -67,6 +67,9 @@ properties:
   reg:
     maxItems: 1
 
+  clocks:
+    maxItems: 1
+
   "#address-cells":
     const: 1
 
@@ -249,6 +252,22 @@ allOf:
 
           unevaluatedProperties: false
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - rockchip,rk3588-vo-grf
+
+    then:
+      required:
+        - clocks
+
+    else:
+      properties:
+        clocks: false
+
+
 examples:
   - |
     #include <dt-bindings/clock/rk3399-cru.h>