dt-bindings: gpu: mali-bifrost: describe clocks for the rk356x gpu

The Bifrost GPU in Rockchip RK356x SoCs has a core and a bus clock.
Reflect this in the SoC specific part of the binding.
Signed-off-by: Alex Bee <knaerzche@gmail.com>
[move the changes to the SoC section]
Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209215549.94524-2-michael.riesch@wolfvision.net

Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml

@@ -159,6 +159,21 @@ allOf:
         power-domains:
           maxItems: 1
         sram-supply: false
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: rockchip,rk3568-mali
+    then:
+      properties:
+        clocks:
+          minItems: 2
+        clock-names:
+          items:
+            - const: gpu
+            - const: bus
+      required:
+        - clock-names
 
 examples:
   - |