Revert "wifi: iwlwifi: clean up config macro"

This reverts commit b6abf63e.

This is causing major merge conflicts with the changes in
wireless, where we reverted some changes. Revert this for
now to avoid having to solve that problem. We can redo it
on top of wireless-next with wireless merged back later.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>