legacy/msm8660: Enable support for LPA/Tunnel audio playback

 - based off http://review.cyanogenmod.org/#/c/53196

Change-Id: I12edbf103fe3a5a81451d2b4242bf77342b64ff9
msm8660: update audio policy

based off http://review.cyanogenmod.org/#/c/52982/

Change-Id: I8fdd2cec421e7b1b715c899c8d10b7a00261a2d4