dt-bindings: clock: rpmcc: Document msm8976 compatible

Support for MSM8976 was added to the clk-smd-rpm driver: let's
document here the newly added compatible string.

Signed-off-by: AngeloGioacchino Del Regno <kholk11@gmail.com>
Link: https://lkml.kernel.org/r/20191031112951.35850-3-kholk11@gmail.com
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Documentation/devicetree/bindings/clock/qcom,rpmcc.txt

@@ -14,6 +14,7 @@ Required properties :
 			"qcom,rpmcc-apq8060", "qcom,rpmcc"
 			"qcom,rpmcc-msm8916", "qcom,rpmcc"
 			"qcom,rpmcc-msm8974", "qcom,rpmcc"
+			"qcom,rpmcc-msm8976", "qcom,rpmcc"
 			"qcom,rpmcc-apq8064", "qcom,rpmcc"
 			"qcom,rpmcc-msm8996", "qcom,rpmcc"
 			"qcom,rpmcc-msm8998", "qcom,rpmcc"