ASoC: msm8x16-wcd: update TX3 ground reference bit properly

TX3 ground reference bit is not maintained properly during
the record session over main mic and headset.

Update codec driver micbias function to maintain this bit
properly

Change-Id: Idcf826b003f0dc2946bf4afd71293e55332eddd6
Signed-off-by: Santosh Mardi <gsantosh@codeaurora.org>