ASoC: codec duplicated callback function goes to component on ak4671

codec driver and component driver has duplicated callback functions,
and codec side functions are just copied to component side when
register timing. This was quick-hack, but no longer needed.
This patch moves these functions from codec driver to component driver.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>