ASoC: wcd9304: recalibrate microphone ground voltage

Different clock sources can affect mbhc voltage inconsistent measurement
accumulation which consecutively results in inaccurate button detection.
Recalibrate ground voltage on dce handler to enhance mbhc button detection
accuracy.

CRs-Fixed: 495526
Change-Id: I30c548677a85febe644da1dfb4ce1c6622c8a658
Signed-off-by: Simmi Pateriya <simmip@codeaurora.org>
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>