dt-bindings: clock: add loongson-2 clock

Add the Loongson-2 clock binding with DT schema format using
json-schema.
Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221129034157.15036-4-zhuyinbo@loongson.cnSigned-off-by: Stephen Boyd <sboyd@kernel.org>

Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/loongson,ls2k-clk.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Loongson-2 SoC Clock Control Module
+
+maintainers:
+  - Yinbo Zhu <zhuyinbo@loongson.cn>
+
+description: |
+  Loongson-2 SoC clock control module is an integrated clock controller, which
+  generates and supplies to all modules.
+
+properties:
+  compatible:
+    enum:
+      - loongson,ls2k-clk
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: 100m ref
+
+  clock-names:
+    items:
+      - const: ref_100m
+
+  '#clock-cells':
+    const: 1
+    description:
+      The clock consumer should specify the desired clock by having the clock
+      ID in its "clocks" phandle cell. See include/dt-bindings/clock/loongson,ls2k-clk.h
+      for the full list of Loongson-2 SoC clock IDs.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - '#clock-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    ref_100m: clock-ref-100m {
+        compatible = "fixed-clock";
+        #clock-cells = <0>;
+        clock-frequency = <100000000>;
+        clock-output-names = "ref_100m";
+    };
+
+    clk: clock-controller@1fe00480 {
+        compatible = "loongson,ls2k-clk";
+        reg = <0x1fe00480 0x58>;
+        #clock-cells = <1>;
+        clocks = <&ref_100m>;
+        clock-names = "ref_100m";
+    };

MAINTAINERS

@@ -12199,6 +12199,7 @@ LOONGSON-2 SOC SERIES CLOCK DRIVER
 M:	Yinbo Zhu <zhuyinbo@loongson.cn>
 L:	linux-clk@vger.kernel.org
 S:	Maintained
+F:	Documentation/devicetree/bindings/clock/loongson,ls2k-clk.yaml
 F:	include/dt-bindings/clock/loongson,ls2k-clk.h
 
 LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)