usbaudio: reset profile on device disconnect

Reset ALSA device profile on disconnect event. Entries like
supported sample rates, channel counts, formats will be repopulated
on next connect.

Change-Id: I27d3b7fd7ff22646996f58c53de08547b1a1fb6a
CRs-Fixed: 765434
Merge pull request #1 from CyanogenMod/cm-12.0

usbaudio: reset profile on device disconnect