iwlwifi: continue namespace changes - fix CONFIG variables

- Remove 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.
- Modify a few places where the CONFIG variables were named
  incorrectly: all changes are to comments only.

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