Specifically, use 'const' for the key passed to the 'setkey' method
and 'const' for the 'iv' passed to the 'reinit' method.
Reviewed by: cem
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D21347
Keep xform.c as a meta-file including the broken out bits
existing code that includes xform.c continues to work as normal
Individual algorithms can now be reused elsewhere, including outside
of the kernel
Reviewed by: bapt (previous version), gnn, delphij
Approved by: secteam
MFC after: 1 week
Sponsored by: ScaleEngine Inc.
Differential Revision: https://reviews.freebsd.org/D4674