iwl3945: move structures from iwl-3945.h to iwl-dev.h

The patch moves few structres from iwl-3945.h to iwl-dev.h.

Signed-off-by: Abhijeet Kolekar <abhijeet.kolekar@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>