blk-mq: register device instead of disk

Enable devices without a gendisk instance to register itself with blk-mq
and expose the associated multi-queue sysfs entries.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index f87a7e7..9cc8d7c 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -704,7 +704,7 @@
 	kobject_uevent(&q->kobj, KOBJ_ADD);
 
 	if (q->mq_ops)
-		blk_mq_register_disk(disk);
+		blk_mq_register_dev(dev, q);
 
 	if (!q->request_fn)
 		return 0;
@@ -729,7 +729,7 @@
 		return;
 
 	if (q->mq_ops)
-		blk_mq_unregister_disk(disk);
+		blk_mq_unregister_dev(disk_to_dev(disk), q);
 
 	if (q->request_fn)
 		elv_unregister_queue(q);