dt-bindings: mailbox: qcom-ipcc: Add SM8750

Document compatible for Qualcomm SM8750 SoC IPCC, compatible with
existing generic fallback.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

Author: krzk

Documentation/devicetree/bindings/mailbox/qcom-ipcc.yaml

@@ -39,6 +39,7 @@ properties:
           - qcom,sm8450-ipcc
           - qcom,sm8550-ipcc
           - qcom,sm8650-ipcc
+          - qcom,sm8750-ipcc
           - qcom,x1e80100-ipcc
       - const: qcom,ipcc