ASoC: wm8750: convert to the json-schema

This helps validating DTS files.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210512205926.780-1-zajec5@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/wm8750.yaml

@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/wm8750.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: WM8750 and WM8987 audio CODECs
+
+description: |
+  These devices support both I2C and SPI (configured with pin strapping
+  on the board).
+
+maintainers:
+  - Mark Brown <broonie@kernel.org>
+
+properties:
+  compatible:
+    enum:
+      - wlf,wm8750
+      - wlf,wm8987
+
+  reg:
+    description:
+      The I2C address of the device for I2C, the chip select number for SPI
+    maxItems: 1
+
+additionalProperties: false
+
+required:
+  - reg
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        codec@1a {
+            compatible = "wlf,wm8750";
+            reg = <0x1a>;
+        };
+    };