EAP-MSCHAPv2 peer: Add option to disable password retry query

EAP-MSCHAPv2 peer: Add option to disable password retry query

wpa_supplicant used to request user to re-enter username/password if the
server indicated that EAP-MSCHAPv2 (e.g., in PEAP Phase 2)
authentication failed (E=691), but retry is allowed (R=1). This is a
reasonable default behavior, but there may be cases where it is more
convenient to close the authentication session immediately rather than
wait for user to do something.

Add a new "mschapv2_retry=0" option to the phase2 field to allow the
retry behavior to be disabled. This will make wpa_supplicant abort
authentication attempt on E=691 regardless of whether the server allows
retry.

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