This is needed to fix PTK derivation to use correct length. Previously,
64-octet PTK may have been derived if the authenticator did not already
have a STA entry. Now, the correct pairwise cipher suite is learned when
then PMK-R1 SA is received.
The three existing enums were already depending on using the same
values in couple of places and it is just simpler to standardize on
one of these to avoid need for mapping between different enums for
the exact same thing.
Doxygen and some build tools may get a bit confused about same file
name being used in different directories. Clean this up a bit by
renaming some of the duplicated file names in src/ap.
