nvme/host: Add missing blk_integrity tag_size + flags assignments

While doing recent bring-up of nvme/host with target-core T10-PI,
I noticed /sys/block/nvme*/integrity/device_is_integrity_capable
was false, and /sys/block/nvme*/integrity/tag_size contained
a bogus value.

AFAICT outside of blk_integrity_compare() for DM + MD these
are informational values, but go ahead and add the missing
assignments for nvme/host to match what SCSI does within
sd_dif_config_host() for consistency's sake.

Cc: Keith Busch <keith.busch@intel.com>
Cc: Jay Freyensee <james.p.freyensee@intel.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Sagi Grimberg <sagig@grimberg.me>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Sagi Grimberg <sagi at grimberg.me>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>