dt-bindings: clock: Add YAML schemas for the QCOM DISPCC clock bindings

The DISPCC clock provider have a bunch of generic properties that
are needed in a device tree. Add a YAML schemas for those.
Signed-off-by: Taniya Das <tdas@codeaurora.org>
Link: https://lkml.kernel.org/r/1573812245-23827-2-git-send-email-tdas@codeaurora.orgReviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

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

-Qualcomm Technologies, Inc. Display Clock Controller Binding
-------------------------------------------------------------
-
-Required properties :
-
-- compatible : shall contain "qcom,sdm845-dispcc"
-- reg : shall contain base register location and length.
-- #clock-cells : from common clock binding, shall contain 1.
-- #reset-cells : from common reset binding, shall contain 1.
-- #power-domain-cells : from generic power domain binding, shall contain 1.
-
-Example:
-	dispcc: clock-controller@af00000 {
-		compatible = "qcom,sdm845-dispcc";
-		reg = <0xaf00000 0x100000>;
-		#clock-cells = <1>;
-		#reset-cells = <1>;
-		#power-domain-cells = <1>;
-	};

Documentation/devicetree/bindings/clock/qcom,dispcc.yaml

+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bindings/clock/qcom,dispcc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Display Clock & Reset Controller Binding
+
+maintainers:
+  - Taniya Das <tdas@codeaurora.org>
+
+description: |
+  Qualcomm display clock control module which supports the clocks, resets and
+  power domains.
+
+properties:
+  compatible:
+    enum:
+      - qcom,sdm845-dispcc
+
+  clocks:
+    minItems: 1
+    maxItems: 2
+    items:
+      - description: Board XO source
+      - description: GPLL0 source from GCC
+
+  clock-names:
+    items:
+      - const: xo
+      - const: gpll0
+
+  '#clock-cells':
+    const: 1
+
+  '#reset-cells':
+    const: 1
+
+  '#power-domain-cells':
+    const: 1
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - '#clock-cells'
+  - '#reset-cells'
+  - '#power-domain-cells'
+
+examples:
+  # Example of DISPCC with clock node properties for SDM845:
+  - |
+    clock-controller@af00000 {
+      compatible = "qcom,sdm845-dispcc";
+      reg = <0xaf00000 0x10000>;
+      clocks = <&rpmhcc 0>, <&gcc 24>;
+      clock-names = "xo", "gpll0";
+      #clock-cells = <1>;
+      #reset-cells = <1>;
+      #power-domain-cells = <1>;
+     };
+...