This adds most of the new frame format and identifier definitions from IEEE
802.11w/D6.0. In addition, the RSN IE capability field values for MFP is
replaced with the new two-bit version with MFPC (capable) and MFPR
(required) processing.
The old version was using struct wpa_sm::bssid which is not necessarily
updated to point to the correct target address when doing over-the-air FT
since the address is used before the association has actually been
completed.
