iwl3945: fix deadlock on suspend

This patch fixes iwl3945 deadlock during suspend by moving notify_mac out
of iwl3945 mutex. This is a portion of the same fix for iwlwifi by Tomas.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
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>