IEEE 802.11w/D6.0 defines new AKMPs to indicate SHA256-based algorithms for
key derivation (and AES-CMAC for EAPOL-Key MIC). Add support for using new
AKMPs and clean up AKMP processing with helper functions in defs.h.
crypto_binding=# in phase1 network parameter can now be used to change the
PEAPv0 cryptobinding behavior (0 = do not use, 1 = optional (default),
2 = required).
