iwlwifi: mvm: fix packet injection

We need to have a station and a queue for the monitor
interface to be able to inject traffic. We used to have
this traffic routed to the auxiliary queue, but this queue
isn't scheduled for the station we had linked to the
monitor vif.

Allocate a new queue, link it to the monitor vif's station
and make that queue use the BE fifo.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=196715



Cc: stable@vger.kernel.org
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>