ASoC: mediatek: mt8186: add mt8186-mt6366-da7219-max98357 document

Add document for mt8186 board with mt6366, da7219 and max98357.
Signed-off-by: Jiaxin Yu <jiaxin.yu@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220718162204.26238-7-jiaxin.yu@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/mt8186-mt6366-da7219-max98357.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/mt8186-mt6366-da7219-max98357.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mediatek MT8186 with MT6366, DA7219 and MAX98357 ASoC sound card driver
+
+maintainers:
+  - Jiaxin Yu <jiaxin.yu@mediatek.com>
+
+description:
+  This binding describes the MT8186 sound card.
+
+properties:
+  compatible:
+    enum:
+      - mediatek,mt8186-mt6366-da7219-max98357-sound
+
+  mediatek,platform:
+    $ref: "/schemas/types.yaml#/definitions/phandle"
+    description: The phandle of MT8186 ASoC platform.
+
+  headset-codec:
+    type: object
+    additionalProperties: false
+    properties:
+      sound-dai:
+        maxItems: 1
+    required:
+      - sound-dai
+
+  playback-codecs:
+    type: object
+    additionalProperties: false
+    properties:
+      sound-dai:
+        items:
+          - description: phandle of dp codec
+          - description: phandle of l channel speaker codec
+          - description: phandle of r channel speaker codec
+        minItems: 2
+    required:
+      - sound-dai
+
+additionalProperties: false
+
+required:
+  - compatible
+  - mediatek,platform
+  - headset-codec
+  - playback-codecs
+
+examples:
+  - |
+
+    sound: mt8186-sound {
+        compatible = "mediatek,mt8186-mt6366-da7219-max98357-sound";
+        mediatek,platform = <&afe>;
+        pinctrl-names = "aud_clk_mosi_off",
+                        "aud_clk_mosi_on";
+        pinctrl-0 = <&aud_clk_mosi_off>;
+        pinctrl-1 = <&aud_clk_mosi_on>;
+
+        headset-codec {
+            sound-dai = <&da7219>;
+        };
+
+        playback-codecs {
+            sound-dai = <&anx_bridge_dp>,
+                        <&max98357a>;
+        };
+    };
+
+...