ASoC: codecs: wcd934x: add mbhc support

WCD934x 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 feature via common mbhc layer.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210604115230.23259-4-srinivas.kandagatla@linaro.org


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