Allow RSNE in EAPOL-Key msg 3/4 to be replaced for testing purposes

Allow RSNE in EAPOL-Key msg 3/4 to be replaced for testing purposes

The new hostapd configuration parameter rsne_override_eapol can now be
used similarly to the previously added rsnxe_override_eapol to override
(replace contents or remove) RSNE in EAPOL-Key msg 3/4. This can be used
for station protocol testing to verify sufficient checks for RSNE
modification between the Beacon/Probe Response frames and EAPOL-Key msg
3/4.

Signed-off-by: Jouni Malinen <j@w1.fi>