ASoC: mediatek: common: add soundcard driver common code

Add common code to support of_node of codec parsing, so codec phandle
can be assigned by sound-dai in dts.

Signed-off-by: Trevor Wu <trevor.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230116034131.23943-12-trevor.wu@mediatek.com


Signed-off-by: Mark Brown <broonie@kernel.org>