This adds a new getSessionId() callback for EAP peer methods to allow
EAP Session-Id to be derived. This commits implements this for EAP-FAST,
EAP-GPSK, EAP-IKEv2, EAP-PEAP, EAP-TLS, and EAP-TTLS.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>