iwlwifi: rename 4965 to AGN

This patch renames driver name from 4965 to AGN
The driver supports both 4965AGN and 5000AGN family

The driver's original module name iwl4965.ko remains as an alias

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