Revert "mac80211: remove exposing 'mfp' to drivers"

This reverts commit 5c48f120.

Some device drivers (ath10k) offload part of aggregation including AddBA/DelBA
negotiations to firmware. In such scenario, the PMF configuration of
the station needs to be provided to driver to enable encryption of
AddBA/DelBA action frames.

Signed-off-by: Tamizh chelvam <c_traja@qti.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>