ASoC: msm: Enable MBHC 5-pole plug detection

Enable MBHC (Multi Button Headset Control) 5-pole
plug detection so as to detect the presence of
second microphone whenever any accessory is inserted
in to the headset jack.

Change-Id: I53dda0d18006109c19a1cd8ce0bc4df45a13f0bf
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>