ASoC: dt-bindings: wm8728: Convert to dtschema

Convert the WM8728 audio CODEC bindings to DT schema
Signed-off-by: Saalim Quadri <danascape@gmail.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230417204323.137681-1-danascape@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/wlf,wm8728.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/wlf,wm8728.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: WM8728 audio CODEC
+
+maintainers:
+  - patches@opensource.cirrus.com
+
+allOf:
+  - $ref: dai-common.yaml#
+
+properties:
+  compatible:
+    const: wlf,wm8728
+
+  reg:
+    maxItems: 1
+
+  "#sound-dai-cells":
+    const: 0
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        codec@1a {
+            compatible = "wlf,wm8728";
+            reg = <0x1a>;
+        };
+    };

Documentation/devicetree/bindings/sound/wm8728.txt

-WM8728 audio CODEC
-
-This device supports both I2C and SPI (configured with pin strapping
-on the board).
-
-Required properties:
-
-  - compatible : "wlf,wm8728"
-
-  - reg : the I2C address of the device for I2C, the chip select
-          number for SPI.
-
-Example:
-
-wm8728: codec@1a {
-	compatible = "wlf,wm8728";
-	reg = <0x1a>;
-};