ASoC: cs42l42: Correct definition of ADC Volume control

The ADC volume is a signed 8-bit number with range -97 to +12,
with -97 being mute. Use a SOC_SINGLE_S8_TLV() to define this
and fix the DECLARE_TLV_DB_SCALE() to have the correct start and
mute flag.

Fixes: 2c394ca7

 ("ASoC: Add support for CS42L42 codec")
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20210729170929.6589-1-rf@opensource.cirrus.com


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