ASoC: WCD9310: Pause headset polling before switching MBHC Mic Bias

With headset inserted and no recording, the MIC BIAS is switched to
VDDIO to avoid noise on Headphone due to button polling. When this
switch happens, it is required to pause the headset polling before
the switch and restart it again when the switch is done

This will make the MIC BIAS switch smooth and will avoid click/pop
noise that may happen during the switch

Change-Id: I092d1915b379173b88a38584bf1701cce833c9ae
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>