Current ALSA SoC has many snd_soc_dai_xxx() function which is
using dai->driver->ops->xxx.
But, some of them are implemented as snd_soc_dai_xxx(),
but others are directly using dai->driver->ops->xxx.
Because of it, the code is not easy to read.

This patch creats new soc-dai.c and moves snd_soc_dai_xxx()
functions into it.
One exception is snd_soc_dai_is_dummy() which is based on
soc-utils local variable. We need to keep it as-is there.

Others which is directly using dai->driver->ops->xxx will be
implemented at soc-dai.c by incremental patches.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/871ryij1r6.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>