ASoC: mbhc: fix the no audio issue in the voice call

The headset removal during the voice call causes the master bias to be
turned down impairing the speaker functionality.
Fix by removing the disable sequence of the MASTER_BIAS
during the headset plugout.

CRs-Fixed: 684711
Change-Id: I8ba382549f7efb08bda9412d0c401a9e7d78915d
Signed-off-by: Aviral Gupta <aviralg@codeaurora.org>