ASoC: dt-bindings: samsung,smdk5250: convert to dtschema

Convert the audio complex on SMDK5250 boards with Samsung Exynos SoC to
DT schema format.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220129122430.45694-3-krzysztof.kozlowski@canonical.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/samsung,smdk-wm8994.txt

-Samsung SMDK audio complex
-
-Required properties:
-- compatible : "samsung,smdk-wm8994"
-- samsung,i2s-controller: The phandle of the Samsung I2S0 controller
-- samsung,audio-codec: The phandle of the WM8994 audio codec
-Example:
-
-sound {
-		compatible = "samsung,smdk-wm8994";
-
-		samsung,i2s-controller = <&i2s0>;
-		samsung,audio-codec = <&wm8994>;
-};

Documentation/devicetree/bindings/sound/samsung,smdk5250.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/samsung,smdk5250.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung SMDK5250 audio complex with WM8994 codec
+
+maintainers:
+  - Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
+  - Sylwester Nawrocki <s.nawrocki@samsung.com>
+
+properties:
+  compatible:
+    const: samsung,smdk-wm8994
+
+  samsung,audio-codec:
+    description: Phandle to the audio codec.
+    $ref: /schemas/types.yaml#/definitions/phandle
+
+  samsung,i2s-controller:
+    description: Phandle to the Samsung I2S controller.
+    $ref: /schemas/types.yaml#/definitions/phandle
+
+required:
+  - compatible
+  - samsung,audio-codec
+  - samsung,i2s-controller
+
+additionalProperties: false
+
+examples:
+  - |
+    sound {
+        compatible = "samsung,smdk-wm8994";
+        samsung,i2s-controller = <&i2s0>;
+        samsung,audio-codec = <&wm8994>;
+    };