dt-bindings: mediatek: mt6359: add codec document

This patch adds MediaTek MT6359 codec document.
Signed-off-by: Jiaxin Yu <jiaxin.yu@mediatek.com>
Link: https://lore.kernel.org/r/1597913493-10747-3-git-send-email-jiaxin.yu@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/mt6359.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/mt6359.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mediatek MT6359 Codec Device Tree Bindings
+
+maintainers:
+  - Eason Yen <eason.yen@mediatek.com>
+  - Jiaxin Yu <jiaxin.yu@mediatek.com>
+  - Shane Chien <shane.chien@mediatek.com>
+
+description: |
+  The communication between MT6359 and SoC is through Mediatek PMIC wrapper.
+  For more detail, please visit Mediatek PMIC wrapper documentation.
+  Must be a child node of PMIC wrapper.
+
+properties:
+  mediatek,dmic-mode:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Indicates how many data pins are used to transmit two channels of PDM
+      signal. 0 means two wires, 1 means one wire. Default value is 0.
+    enum:
+      - 0 # one wire
+      - 1 # two wires
+
+  mediatek,mic-type-0:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Specifies the type of mic type connected to adc0
+
+    enum:
+      - 0 # IDLE - mic in turn-off status
+      - 1 # ACC - analog mic with alternating coupling
+      - 2 # DMIC - digital mic
+      - 3 # DCC - analog mic with direct couping
+      - 4 # DCC_ECM_DIFF - analog electret condenser mic with differential mode
+      - 5 # DCC_ECM_SINGLE - analog electret condenser mic with single mode
+
+  mediatek,mic-type-1:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Specifies the type of mic type connected to adc1
+
+  mediatek,mic-type-2:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Specifies the type of mic type connected to adc2
+
+additionalProperties: false
+
+examples:
+  - |
+    mt6359codec: mt6359codec {
+      mediatek,dmic-mode = <0>;
+      mediatek,mic-type-0 = <2>;
+    };
+
+...