nvme: Add Support for Opal: Unlock from S3 & Opal Allocation/Ioctls

This patch implements the necessary logic to unlock an Opal
enabled device coming back from an S3.

The patch also implements the SED/Opal allocation necessary to support
the opal ioctls.

Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>