ERP: Add support for ERP on EAP peer

ERP: Add support for ERP on EAP peer

Derive rRK and rIK on EAP peer if ERP is enabled. The new wpa_supplicant
network configuration parameter erp=1 can now be used to configure the
EAP peer to derive EMSK, rRK, and rIK at the successful completion of an
EAP authentication method. This functionality is not included in the
default build and can be enabled with CONFIG_ERP=y.

If EAP authenticator indicates support for re-authentication protocol,
initiate this with EAP-Initiate/Re-auth and complete protocol when
receiving EAP-Finish/Re-auth.

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