Revert "mac80211: add pointer for driver use to key"
This reverts commit f9a060f4b2003eb7350762e60dfc576447e44bad.
No driver has turned up needing this functionality, and I've just
implemented the functionality I wanted this for in a different
way. Thus, remove it again, until somebody shows up with a need
for having it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>