ASoC: mediatek: dt-bindings: modify machine bindings for SOF

Add SOF related field.
1. Add a property "mediatek,adsp", Only when adsp phandle could be
retrieved, from DTS, the SOF related part of machine driver is executed.
2. Add a property "mediatek,dai-link" to support dai-links could be
specified from DTS

Signed-off-by: chunxu.li <chunxu.li@mediatek.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220824122319.23918-3-chunxu.li@mediatek.com


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