devicetree: bindings: Document qcom,mmcc

Document the multimedia clock controller found on Qualcomm devices

Cc: <devicetree@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

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

+Qualcomm Multimedia Clock & Reset Controller Binding
+----------------------------------------------------
+
+Required properties :
+- compatible : shall contain only one of the following:
+
+			"qcom,mmcc-msm8660"
+			"qcom,mmcc-msm8960"
+			"qcom,mmcc-msm8974"
+
+- reg : shall contain base register location and length
+- #clock-cells : shall contain 1
+- #reset-cells : shall contain 1
+
+Example:
+	clock-controller@4000000 {
+		compatible = "qcom,mmcc-msm8960";
+		reg = <0x4000000 0x1000>;
+		#clock-cells = <1>;
+		#reset-cells = <1>;
+	};