ASoC: pcm3168a: Use fixup instead of constraint for channels and formats

ASoC: pcm3168a: Use fixup instead of constraint for channels and formats

The snd_pcm_hw_constraint_minmax() works fine when a single codec is
connected to a single CPU DAI, but in multicodec or DPCM setup the
constraints placed by the driver will apply to the whole PCM stream (FE
included) and thus prevents more than 8 playback channels for example.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20191008115720.7135-1-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>