iwlwifi: remove HT code from iwl-3945.h

This pach removes HT code from iwl-3945.h - it is not needed here as 3945
does not support HT. The code ended up here during the header file split

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