dt-bindings: gpu: mali-valhall-csf: add mediatek,mt8196-mali variant

The Mali-based GPU on the MediaTek MT8196 SoC uses a separate MCU to
control the power and frequency of the GPU. This is modelled as a power
domain and clock provider.

It lets us omit the OPP tables from the device tree, as those can now be
enumerated at runtime from the MCU.

Add the necessary schema logic to handle what this SoC expects in terms
of clocks and power-domains.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Link: https://patch.msgid.link/20251017-mt8196-gpufreq-v8-1-98fc1cc566a1@collabora.com
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

Documentation/devicetree/bindings/gpu/arm,mali-valhall-csf.yaml

@@ -46,7 +46,9 @@ properties:
     minItems: 1
     items:
       - const: core
-      - const: coregroup
+      - enum:
+          - coregroup
+          - stacks
       - const: stacks
 
   mali-supply: true
@@ -111,6 +113,27 @@ allOf:
         power-domain-names: false
       required:
         - mali-supply
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: mediatek,mt8196-mali
+    then:
+      properties:
+        mali-supply: false
+        sram-supply: false
+        operating-points-v2: false
+        power-domains:
+          maxItems: 1
+        power-domain-names: false
+        clocks:
+          maxItems: 2
+        clock-names:
+          items:
+            - const: core
+            - const: stacks
+      required:
+        - power-domains
 
 examples:
   - |
@@ -146,5 +169,17 @@ examples:
             };
         };
     };
+  - |
+    gpu@48000000 {
+        compatible = "mediatek,mt8196-mali", "arm,mali-valhall-csf";
+        reg = <0x48000000 0x480000>;
+        clocks = <&gpufreq 0>, <&gpufreq 1>;
+        clock-names = "core", "stacks";
+        interrupts = <GIC_SPI 606 IRQ_TYPE_LEVEL_HIGH 0>,
+                     <GIC_SPI 605 IRQ_TYPE_LEVEL_HIGH 0>,
+                     <GIC_SPI 604 IRQ_TYPE_LEVEL_HIGH 0>;
+        interrupt-names = "job", "mmu", "gpu";
+        power-domains = <&gpufreq>;
+    };
 
 ...