ASoC: tlv320aic32x4: Fix TAS2505/TAS2521 channel count

ASoC: tlv320aic32x4: Fix TAS2505/TAS2521 channel count

The TAS2505/TAS2521 does support up to two channels, LEFT and RIGHT,
which are being alternated on the audio data bus by Word Clock, WCLK.
This is documented in TI slau472 2.7.1 Digital Audio Interface. Note
that both the LEFT and RIGHT channels are only used for audio INPUT,
while only the LEFT channel is used for audio OUTPUT.

Fixes: 29baeb11b8344 ("ASoC: tlv320aic32x4: add support for TAS2505")
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Claudius Heine <ch@denx.de>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210708091229.56443-1-marex@denx.de
Signed-off-by: Mark Brown <broonie@kernel.org>