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 <Frank.Li@nxp.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250625161909.2541315-1-Frank.Li@nxp.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>

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

@@ -1,17 +0,0 @@
-LPC32XX PWM controller
-
-Required properties:
-- compatible: should be "nxp,lpc3220-pwm"
-- reg: physical base address and length of the controller's registers
-
-Examples:
-
-pwm@4005c000 {
-	compatible = "nxp,lpc3220-pwm";
-	reg = <0x4005c000 0x4>;
-};
-
-pwm@4005c004 {
-	compatible = "nxp,lpc3220-pwm";
-	reg = <0x4005c004 0x4>;
-};

Documentation/devicetree/bindings/pwm/nxp,lpc3220-pwm.yaml

@@ -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 <Frank.Li@nxp.com>
+
+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>;
+    };
+