add set_rxon_chain op to iwlwifi cfg ops in preparation of
future 3945 porting work.
Signed-off-by: NAbhijeet Kolekar <abhijeet.kolekar@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>