ASoC: ak4613: Improve counting DAI number

Add the startup function to count DAI instead of hw_params.
This change matches the number of opened DAIs.
If this change isn't applied, you may get unexpected error due to
mismatching of count. Since the excution number of hw_params and
shutdown may be different, the mismatching happens.

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