iwlwifi: trivial removal of some 4965 remaining from iwl-agn-rs.h

This patch removes 4965 prefix from comments and one function
in iwl-agn-rs.h

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>