MT6797 with MT6351 CODEC

Required properties:
- compatible: "mediatek,mt6797-mt6351-sound"
- mediatek,platform: the phandle of MT6797 ASoC platform
- mediatek,audio-codec: the phandles of MT6351 codec

Example:

	sound {
		compatible = "mediatek,mt6797-mt6351-sound";
		mediatek,audio-codec = <&mt6351_snd>;
		mediatek,platform = <&afe>;
	};