MFC r289422:
4185 add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Garrett D'Amore <garrett@damore.org>
Author: Matthew Ahrens <mahrens@delphix.com>

illumos/illumos-gate@45818ee124adeaaf947698996b4f4c722afc6d1f

This is only a partial merge of respective ZFS infrastructure changes.
At this moment FreeBSD kernel has no those crypto algorithms, so the
parts of the code to enable them are commented out. When they are
implemented, it will be trivial to plug them in.