iwlwifi: mvm: keep track of tid associated with each queue

When sending the SCD_QUEUE_CONFIG command, the queue is
associated to a specific TID. If later there is a need to
use this TID on a different queue instead, it first needs to
be unassociated from the first queue.

Keep track for every queue what TID is associated with it.

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