Add an alternative sequence for performing the RADIUS ACL check and PSK
fetch. The previously used (macaddr_acl=2, wpa_psk_radius=2) combination
does this during IEEE 802.11 Authentication frame exchange while the new
option (wpa_psk_radius=3) does this during the 4-way handshake. This
allows some more information to be provided to the RADIUS authentication
server.