snd_soc_msm_2x: Fix in-call high pitch buzz; enhance Camcorder TX

- don't use mic bias as it causes high pitch buzz in earpiece during
  calls (it's disabled in the stock firmware as well)
- use both microphones for Camcoder TX (as in stock) and increase
  the decimator volume levels (to get the recordings to acceptable
  volume levels)

Change-Id: Ifbc0b24766193d066e3c02cfe398d6e49362fa9c
Merge "snd_soc_msm_2x: Fix in-call high pitch buzz; enhance Camcorder TX" into cm-10.2