iwlwifi: drop sw_crypto from hw_params.

Each HW supported by iwlwifi is capable of hardware crypto
so drop this flag from hw_params structure.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>