iwlwifi: mvm: use shorter queues for mgmt and auxilary queues

In 22000 devices, aka gen2, the TFS is 256 bytes.
In order to save memory, use shorter TX queue for aux and
mgmt queues, since there isn't much traffic on them.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>