ASoC: tlv320aic32x4: Use snd_soc_update_bits() in aic32x4_hw_params()

Make the code easier to read by using snd_soc_update_bits() over
read/modify/write sequences. Also use separate per-register
variables instead of re-using "data". This can prevent accidental
over-writing and makes it clear for which register each bit value is
intended.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>