iwlwifi: mvm: support dqa-mode scd queue redirection

Make sure that in DQA mode, the SCD's configuration of a
queue is redirected to the lower AC of the streams of the
queue.

Make sure that this queue is redirected to the lowest AC
when adding a new RA/TID to an existing queue. If it isn't -
redirect the queue.

Also, as redirection revealed a bug in the marking of a
shared queue, this patch contains a small fix to make
sure a shared queue maintains the appropriate "shared queue
marking".

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>