Clean up some unused definitions in iwl-4965.h and iwl-3945.h

Move STA_FLG_ definitions to iwl-4965-commands.h
Signed-off-by: NBen Cahill <ben.m.cahill@intel.com>
Signed-off-by: NZhu Yi <yi.zhu@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>