proprietary-files: Commonize msm8960 and msm8960dt where possible

Change-Id: Iddfdb65e5d3f2fbed7eb4d2d65e6a4c3f55eda69
Disable lpa.decode to fix headset playback on msm8960

Change-Id: If1d8139293fe20cb34c80a08df272884e6d02168