iwlwifi: fix the delta for remove max_txq_num patch

BIg portion of "iwlwifi: remove max_txq_num from hw_params" was
missing during merge, here is the fix for it.

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