dt-bindings: arm-smmu: add special case for Google Cheza platform

Cheza fw does not properly program the GPU aperture to allow the
GPU to update the SMMU pagetables for context switches. The board file
works around this by dropping the "qcom,adreno-smmu" compat string.
Add this usecase to arm,smmu.yaml schema.

Signed-off-by: Dmitry Baryshkov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

Author: lumag

Documentation/devicetree/bindings/iommu/arm,smmu.yaml

@@ -69,6 +69,10 @@ properties:
               - qcom,sdm845-smmu-v2
           - const: qcom,adreno-smmu
           - const: qcom,smmu-v2
+      - description: Qcom Adreno GPUs on Google Cheza platform
+        items:
+          - const: qcom,sdm845-smmu-v2
+          - const: qcom,smmu-v2
       - description: Marvell SoCs implementing "arm,mmu-500"
         items:
           - const: marvell,ap806-smmu-500