ASoC: meson: aiu: add hdmi codec control support

Add the codec to codec component which handles the routing between
the audio producers (PCM and I2S) and the synopsys hdmi controller
on the amlogic GX SoC family

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20200213155159.3235792-6-jbrunet@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>