iwlwifi: remove num_of_queues module parameter

This is a hardware parameter, so it shouldn't
be configurable by the user. Users can disable
aggregation (which is the only thing affected)
with 11n_disable.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>