dt-bindings: mediatek: mt8192: add mt8192-mt6358-rt1015-rt5682 document

This patch adds document for the machine board with mt6358, rt1015
and rt5682.
Signed-off-by: Jiaxin Yu <jiaxin.yu@mediatek.com>
Link: https://lore.kernel.org/r/1604390378-23993-10-git-send-email-jiaxin.yu@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/mt8192-mt6359-rt1015-rt5682.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/mt8192-mt6359-rt1015-rt5682.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mediatek MT8192 with MT6359, RT1015 and RT5682 ASoC sound card driver
+
+maintainers:
+   - Jiaxin Yu <jiaxin.yu@mediatek.com>
+   - Shane Chien <shane.chien@mediatek.com>
+
+description:
+  This binding describes the MT8192 sound card.
+
+properties:
+  compatible:
+      const: mediatek,mt8192_mt6359_rt1015_rt5682
+
+  mediatek,platform:
+    $ref: "/schemas/types.yaml#/definitions/phandle"
+    description: The phandle of MT8192 ASoC platform.
+
+additionalProperties: false
+
+required:
+  - compatible
+  - mediatek,platform
+
+examples:
+  - |
+
+    sound: mt8192-sound {
+        compatible = "mediatek,mt8192-mt6359-rt1015-rt5682";
+        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>;
+    };
+
+...