ASoC: meson: aiu: add internal dac codec control support

Add the codec to codec component which handles the routing between
the audio producers and the internal audio DAC found on the amlogic GXL
SoC family

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20200213155159.3235792-7-jbrunet@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>