If the driver maintains its own copy of the PMKSA cache, we need to
clear an entry from the driver whenever wpa_supplicant is dropping
an old PMKSA cache entry.
In addition, start ordering header file includes to be in more
consistent order: system header files, src/utils, src/*, same
directory as the *.c file.
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.
