Codec reg_cache is legacy feature and very few driver only are using
it. But, ALSA SoC framework needs to support it.
Codec will be merged into Component in the future, so, let's remove
legacy and unused feature from framework.
This patch implements ALSA SoC reg_cache feature into driver,
and don't use  ALSA SoC framework's feature.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>