ERP: Fix rIK derivation

ERP: Fix rIK derivation

Unlike the EMSKname and rRK derivations, rIK derivation is actually
using the "optional data" component in the context data (see RFC 5295).
RFC 6696 defines that optional data to be the cryptosuite field for rIK.
This was missing from the previous implementation and that resulted in
incorrect rIK being derived.

In addition, the rIK Label string does not actually include the "EAP "
prefix in the way as the rRK Label in RFC 6696 does. This would also
have resulted in incorrect rIK value.

Fix rIK derivation by adding the cryptosuite value into the KDF context
data and fixing the label string. This change is not backwards
compatible and breaks all ERP use cases (including FILS shared key
authentication) with older (broken) and new (fixed)
hostapd/wpa_supplicant builds.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>