ASoC: wcd9304: Wait enough time during mbhc calibration

If mbhc micbias has a capacitor which is large enough to delay micbias
voltage ramp up/down, initial calibration also needs to delay enough time
after changing mux to be able to calibrate ground and micbias voltage
accurately.  Increase delay to 50ms during calibration and improve
calibration accuracy.

CRs-Fixed: 495526
Change-Id: I8bf1297045565740175292a522168131754e7940
Signed-off-by: Simmi Pateriya <simmip@codeaurora.org>
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>