ASoC: msm8974: Enable RTAC for 8974

Enable Real-Time Audio Calibration for 8974. Allows
tuning of calibration parameters during operation
such as voice call, playback, or record.

Change-Id: I61b8616bb7e5c1e74dc8e140949fc605e5eee342
Signed-off-by: Ben Romberger <bromberg@codeaurora.org>