Support session information on FreeBSD.

Support session information on FreeBSD.

FreeBSD's /dev/crypto does not provide a CIOCGSESSINFO ioctl, but it
does provide other ioctls that can be used to provide similar
functionality.

First, FreeBSD's /dev/crypto defines a CIOCGESSION2 ioctl which accepts
a 'struct session2_op'.  This structure extends 'struct session_op'
with a 'crid' member which can be used to either request an individual
driver by id, or a class of drivers via flags.

To determine if the available drivers for a given algorithm are
accelerated or not, use CIOCGESSION2 to first attempt to create an
accelerated (hardware) session.  If that fails, fall back to
attempting a software session.  In addition, when requesting a new
cipher session, use the current setting of the 'use_softdrivers' flag
to determine the value assigned to 'crid' when invoking CIOCGSESSION2.

Finally, use the returned 'crid' value from CIOCGSESSION2 to look up
the name of the associated driver via the CIOCFINDDEV ioctl.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Ben Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/13468)