dt-bindings: pwm: brcm,iproc-pwm: convert to the json-schema

This helps validating DTS files.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20210512160253.15000-1-zajec5@gmail.comSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/pwm/brcm,iproc-pwm.txt

-Broadcom iProc PWM controller device tree bindings
-
-This controller has 4 channels.
-
-Required Properties :
-- compatible: must be "brcm,iproc-pwm"
-- reg: physical base address and length of the controller's registers
-- clocks: phandle + clock specifier pair for the external clock
-- #pwm-cells: Should be 3. See pwm.yaml in this directory for a
-  description of the cells format.
-
-Refer to clocks/clock-bindings.txt for generic clock consumer properties.
-
-Example:
-
-pwm: pwm@18031000 {
-	compatible = "brcm,iproc-pwm";
-	reg = <0x18031000 0x28>;
-	clocks = <&osc>;
-	#pwm-cells = <3>;
-};

Documentation/devicetree/bindings/pwm/brcm,iproc-pwm.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/brcm,iproc-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom iProc PWM controller
+
+maintainers:
+  - Rafał Miłecki <rafal@milecki.pl>
+
+description:
+  This controller has 4 channels.
+
+allOf:
+  - $ref: pwm.yaml#
+
+properties:
+  compatible:
+    const: brcm,iproc-pwm
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description: external clock
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 3
+
+unevaluatedProperties: false
+
+required:
+  - reg
+  - clocks
+
+examples:
+  - |
+    pwm@18031000 {
+        compatible = "brcm,iproc-pwm";
+        reg = <0x18031000 0x28>;
+        clocks = <&osc>;
+        #pwm-cells = <3>;
+    };