dt-bindings: pwm: keembay: Add bindings for Intel Keem Bay PWM

Add PWM Device Tree bindings documentation for the Intel Keem Bay SoC.
Signed-off-by: Vineetha G. Jaya Kumaran <vineetha.g.jaya.kumaran@intel.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Documentation/devicetree/bindings/pwm/intel,keembay-pwm.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2020 Intel Corporation
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/intel,keembay-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Intel Keem Bay PWM Device Tree Bindings
+
+maintainers:
+  - Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
+
+allOf:
+  - $ref: pwm.yaml#
+
+properties:
+  compatible:
+    enum:
+      - intel,keembay-pwm
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 2
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - '#pwm-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    #define KEEM_BAY_A53_GPIO
+
+    pwm@203200a0 {
+        compatible = "intel,keembay-pwm";
+        reg = <0x203200a0 0xe8>;
+        clocks = <&scmi_clk KEEM_BAY_A53_GPIO>;
+        #pwm-cells = <2>;
+    };