iwlwifi: mvm: don't assume static queue numbers

In a000 devices FW will assign the queue number. Prepare for
that by getting rid of static defines and store them in variables.
Enlarge to u16 since we may have up to 512 queues.

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