dt-bindings: sound: gtm601: convert to YAML

Convert GTM601 binding to the YAML format.
Signed-off-by: David Heidelberg <david@ixit.cz>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230730191742.117013-1-david@ixit.czSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/gtm601.txt

-GTM601 UMTS modem audio interface CODEC
-
-This device has no configuration interface. The sample rate and channels are
-based on the compatible string
-	"option,gtm601" = 8kHz mono
-	"broadmobi,bm818" = 48KHz stereo
-
-Required properties:
-
-  - compatible : one of
-	"option,gtm601"
-	"broadmobi,bm818"
-
-
-Example:
-
-codec: gtm601_codec {
-	compatible = "option,gtm601";
-};

Documentation/devicetree/bindings/sound/option,gtm601.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/option,gtm601.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: GTM601 UMTS modem audio interface CODEC
+
+maintainers:
+  - kernel@puri.sm
+
+description: >
+  This device has no configuration interface. The sample rate and channels are
+  based on the compatible string
+
+properties:
+  compatible:
+    oneOf:
+      - items:  # 48 kHz stereo
+          - const: broadmobi,bm818
+          - const: option,gtm601
+      - const: option,gtm601  # 8 kHz mono
+
+  '#sound-dai-cells':
+    const: 0
+
+required:
+  - compatible
+
+allOf:
+  - $ref: dai-common.yaml#
+
+additionalProperties: false
+
+examples:
+  - |
+    codec {
+        compatible = "option,gtm601";
+        #sound-dai-cells = <0>;
+    };