regulator: qcom,rpmh-regulator: Add compatible for SA8155p-adp board pmic

Add compatible string for pmm8155au pmic found on
the SA8155p-adp board.

Cc: Mark Brown <broonie@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210617051712.345372-3-bhupesh.sharma@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.yaml

@@ -62,6 +62,7 @@ properties:
       - qcom,pm8350c-rpmh-regulators
       - qcom,pm8998-rpmh-regulators
       - qcom,pmi8998-rpmh-regulators
+      - qcom,pmm8155au-rpmh-regulators
       - qcom,pmr735a-rpmh-regulators
       - qcom,pmx55-rpmh-regulators