dt-bindings: display: mediatek: split: add subschema property constraints

The display node in mt8195.dtsi was triggering a CHECK_DTBS error due
to an excessively long 'clocks' property:
  display@14f06000: clocks: [[31, 14], [31, 43], [31, 44]] is too long

To resolve this issue, the constraints for 'clocks' and
other properties within the subschemas will be reinforced.

Fixes: 739058a9c5 ("dt-bindings: display: mediatek: split: add compatible for MT8195")
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Signed-off-by: Moudy Ho <moudy.ho@mediatek.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241007022834.4609-1-moudy.ho@mediatek.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

Documentation/devicetree/bindings/display/mediatek/mediatek,split.yaml

@@ -38,6 +38,7 @@ properties:
     description: A phandle and PM domain specifier as defined by bindings of
       the power controller specified by phandle. See
       Documentation/devicetree/bindings/power/power-domain.yaml for details.
+    maxItems: 1
 
   mediatek,gce-client-reg:
     description:
@@ -57,6 +58,9 @@ properties:
   clocks:
     items:
       - description: SPLIT Clock
+      - description: Used for interfacing with the HDMI RX signal source.
+      - description: Paired with receiving HDMI RX metadata.
+    minItems: 1
 
 required:
   - compatible
@@ -72,9 +76,24 @@ allOf:
             const: mediatek,mt8195-mdp3-split
 
     then:
+      properties:
+        clocks:
+          minItems: 3
+
       required:
         - mediatek,gce-client-reg
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: mediatek,mt8173-disp-split
+
+    then:
+      properties:
+        clocks:
+          maxItems: 1
+
 additionalProperties: false
 
 examples: