sound-soc: fix muted headset mic after button press

this corrects a bug where after pressing the button on a headset the mic becomes muted.

partial commit of "sound-soc: Sound platform and WM1811 changes" by SamsungOSRC

Change-Id: I3593e7f0d19b4450d8a3ec55debaede4f80e01c0
Merge pull request #5 from CyanogenMod/cm-11.0

sound-soc: fix muted headset mic after button press