ASoC: msm8x16-wcd: remove setting ADC gain in driver

In case ADC TX FE gain is set in driver while powerup,
it overrides user setting from mixer_paths xml.

Change-Id: I9f3d01f0b0be0661a442899840b63458a812a94f
CRs-Fixed: 668665
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>