ASoC: cs35l41: Fix max number of TX channels

This device only has 4 TX channels.

Fixes: fe1024d5

 ("ASoC: cs35l41: Combine adjacent register writes")
Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220304150721.3802-3-tanureal@opensource.cirrus.com


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