ASoC: wcd9335: Add support to enable vbat feature

Add support to enable vbat monitor feature on tasha codec.
Vbat module monitors the battery voltage and updates the
gain on rx path if battery voltage falls below certain
threshold value. This module can prevent brown-out
scenarios on the mobile devices when the loads are heavy
on the battery and it can also prolong battery life.

Change-Id: I66bacf3b861618fc44f50a8e22ca3f2f0fc7763b
Signed-off-by: Venkata Narendra Kumar Gutta <vgutta@codeaurora.org>
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>