libnvdimm, blk: add support for blk integrity

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>

drivers/nvdimm/nd.h

@@ -27,6 +27,7 @@ enum {
 	 */
 	ND_MAX_LANES = 256,
 	SECTOR_SHIFT = 9,
+	INT_LBASIZE_ALIGNMENT = 64,
 };
 
 struct nvdimm_drvdata {