ASoC: mediatek: mt8183: move private structure

Move private structure to the beginning of file to declare earlier
so that most functions can see it.

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20190830074240.195166-2-tzungbi@google.com


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