iwlwifi: mvm: handle BAR_FRAME_RELEASE (0xc2) notification

In prior hardware generations (e.g. 9000 series), we received the BAR
frame with fake NSSN information to handle releasing frames from the
reorder buffer for the default queue, the other queues were getting
the FRAME_RELEASE notification in this case.

With multi-TID block-ack, the firmware no longer sends us the BAR
frame because the fake RX is quite big (just the metadata is around
48 bytes or so). Instead, it now sends us one (or multiple) special
release notifications (0xc2). The hardware consumes these as well,
but only generates the FRAME_RELEASE (0xc3) for queues other than
the default queue. We thus need to handle them in the same way we
handle the normal FRAME_RELEASE.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>