ASoC: wcd9xxx: Enable MBHC TxFE when micbias is enabled

When micbias is turned ON for audio recording with headset
plugged in, there can be possible noise on the recorded
data due to micbias polling for button detection. To
avoid the noise on audio recording, it is required to
enable the MBHC TxFE (Front-End). Add support to enable
MBHC TxFE when micbias is being enabled for audio recording.

CRs-fixed: 522829
Change-Id: I0689982edab9204aa4f833e59f979f38d6d34418
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>