ASoC: ak4613: priv has ctrl1 instead of iface

Current priv is using ->iface, but it is not good match
to support TDM. This patch adds ->ctrl1 instead of it.
This is prepare for TDM support.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87bkxgp9lh.wl-kuninori.morimoto.gx@renesas.com


Signed-off-by: Mark Brown <broonie@kernel.org>