iwlwifi: move 3945 specific data into union

To be obviously correct, this patch only modifies
3945 files and the struct definition. A follow-up
patch will create the AGN part of the union.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
5 files changed