dt-bindings: arm-smmu: Add compatible for SM8550 SoC

Add the SoC specific compatible for SM8550 implementing
arm,mmu-500.

Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230207-topic-sm8550-upstream-smmu-bindings-v3-1-cb15a7123cfe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>

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

@@ -53,6 +53,7 @@ properties:
               - qcom,sm8250-smmu-500
               - qcom,sm8350-smmu-500
               - qcom,sm8450-smmu-500
+              - qcom,sm8550-smmu-500
           - const: qcom,smmu-500
           - const: arm,mmu-500
 
@@ -389,6 +390,7 @@ allOf:
               - qcom,sm6375-smmu-500
               - qcom,sm8350-smmu-500
               - qcom,sm8450-smmu-500
+              - qcom,sm8550-smmu-500
     then:
       properties:
         clock-names: false