ASoC: max9860: new driver

This is a driver for the MAX9860 Mono Audio Voice Codec.

https://datasheets.maximintegrated.com/en/ds/MAX9860.pdf

This driver does not support sidetone since the DVST register field is
backwards with the mute near the maximum level instead of the minimum.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/Kconfig

@@ -84,6 +84,7 @@ config SND_SOC_ALL_CODECS
 	select SND_SOC_MAX98925 if I2C
 	select SND_SOC_MAX98926 if I2C
 	select SND_SOC_MAX9850 if I2C
+	select SND_SOC_MAX9860 if I2C
 	select SND_SOC_MAX9768 if I2C
 	select SND_SOC_MAX9877 if I2C
 	select SND_SOC_MC13783 if MFD_MC13XXX
@@ -547,6 +548,11 @@ config SND_SOC_MAX98926
 config SND_SOC_MAX9850
 	tristate
 
+config SND_SOC_MAX9860
+	tristate "Maxim MAX9860 Mono Audio Voice Codec"
+	depends on I2C
+	select REGMAP_I2C
+
 config SND_SOC_PCM1681
 	tristate "Texas Instruments PCM1681 CODEC"
 	depends on I2C