ASoC: max98088: add support for noise gate reg

Add support for Noise Gate Threshold reg (ANTH reg 0x40 bit 4 to 7)

References:
 - https://datasheets.maximintegrated.com/en/ds/MAX98089.pdf

, p75

Signed-off-by: Tommaso Merciai <tommaso.merciai@amarulasolutions.com>
Link: https://lore.kernel.org/r/20220825101714.81580-1-tommaso.merciai@amarulasolutions.com


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