media: Fix visibility of destructor

 * This was removed in 3ed51e2299931c8fe8b21ca5a4a0780a6846b2cc, but
   it is still needed by the legacy audio drivers.

Change-Id: If4da23077be8c00577b63991ad998fca41e85c01
Merge remote-tracking branch 'cm/cm-11.0' into HEAD