Add AES-CCM encryption, and plumb into OCF.

Add AES-CCM encryption, and plumb into OCF.

This commit essentially has three parts:

* Add the AES-CCM encryption hooks.  This is in and of itself fairly small,
as there is only a small difference between CCM and the other ICM-based
algorithms.
* Hook the code into the OpenCrypto framework.  This is the bulk of the
changes, as the algorithm type has to be checked for, and the differences
between it and GCM dealt with.
* Update the cryptocheck tool to be aware of it.  This is invaluable for
confirming that the code works.

This is a software-only implementation, meaning that the performance is very
low.

Sponsored by:	iXsystems Inc.
Differential Revision:	https://reviews.freebsd.org/D19090