ASoC: cs53l30: Correct number of volume levels on SX controls

ASoC: cs53l30: Correct number of volume levels on SX controls

[ Upstream commit 7fbd6dd68127927e844912a16741016d432a0737 ]

This driver specified the maximum value rather than the number of volume
levels on the SX controls, this is incorrect, so correct them.

Reported-by: David Rhodes <david.rhodes@cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220602162119.3393857-4-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>