ASoC: codecs: wcd938x: add Multi Button Headset Control support

WCD938x has Multi Button Headset Control hardware to support Headset
insertion, type detection, 8 headset buttons detection, Over Current
detection and Impedence measurements.
This patch adds support for this using wcd-mbhc apis.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210716105918.7301-1-srinivas.kandagatla@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/Kconfig

@@ -1580,6 +1580,7 @@ config SND_SOC_WCD938X
 config SND_SOC_WCD938X_SDW
 	tristate "WCD9380/WCD9385 Codec - SDW"
 	select SND_SOC_WCD938X
+	select SND_SOC_WCD_MBHC
 	depends on SOUNDWIRE
 	select REGMAP_SOUNDWIRE
 	help