hammerhead: Better USB audio support

 * Use new QCOM USB audio path which uses the AFE proxy.
 * This fixes the issues with skips and drops when UI sounds play.

Change-Id: I9941d49b669208959353805f43f51874a415eba3
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_device_lge_hammerhead into cd-4.4