msm8960-common: enable mtp usb connection type

Patch set 1: initial
Patch set 2: allow for distinct mtp and mtp+adb product ids and remove infeasible combination mtp+mass_storage

Change-Id: I4812489313ddfbd85d691b7cfce4b23db3a8031e
Merge remote-tracking branch 'upstream/cm-10.1' into cm-10.1