dt-bindings: pwm: Convert lpc32xx-pwm.txt to yaml format

Convert pc32xx-pwm.txt to yaml format.

Additional changes:
- add ref to pwm.yaml
- add clocks
- restrict #pwm-cells to 3

Signed-off-by: Frank Li <[email protected]>
Reviewed-by: Vladimir Zapolskiy <[email protected]>
Reviewed-by: Rob Herring (Arm) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Uwe Kleine-König <[email protected]>

Author: nxpfrankli

Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt

@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/nxp,lpc3220-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP LPC32XX PWM controller
+
+maintainers:
+  - Frank Li <[email protected]>
+
+properties:
+  compatible:
+    enum:
+      - nxp,lpc3220-pwm
+      - nxp,lpc3220-motor-pwm
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  '#pwm-cells':
+    const: 3
+
+required:
+  - compatible
+  - reg
+  - '#pwm-cells'
+
+allOf:
+  - $ref: pwm.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    pwm@4005c000 {
+        compatible = "nxp,lpc3220-pwm";
+        reg = <0x4005c000 0x4>;
+        #pwm-cells = <3>;
+    };
+