libnvdimm, blk: add support for blk integrity

libnvdimm, blk: add support for blk integrity

Orabug: 22913653

Support multiple block sizes (sector + metadata) for nd_blk in the
same way as done for the BTT. Add the idea of an 'internal' lbasize,
which is properly aligned and padded, and store metadata in this space.

Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
(cherry picked from commit fcae695737fca0849c18db814d9d8de05c0fd2a2)
Signed-off-by: Dan Duval <dan.duval@oracle.com>