ASoC: mediatek: mt8183-da7219: support machine driver with rt1015

Supports machine driver with rt1015 ("mt8183-da7219-rt1015").  Embeds in
existing mt8183-da7219-max98357.c because they share most of the code.

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20200709122445.1584497-6-tzungbi@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>