ASoC: wcd9xxx: Avoid mic schmitt trigger while finding plug type

Do not enable mic schmitt trigger when the plug type
determination work is interrupted by another mechanical
or electrical mbhc interrupt. Otherwise, enabling mic
schmitt trigger will cause spurious unwanted electrical
interrupts to be generated while plug type is getting
determined.

Change-Id: I3dce10b874c903ec517a6683cbcbc8d2a3d82c92
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>