blk-mq: provide dummy blk_mq_map_queue_type() helper

Doesn't do anything right now, but it's needed as a prep patch
to get the interfaces right.

While in there, correct the blk_mq_map_queue() CPU type to an unsigned
int.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

block/blk-mq.h

@@ -73,13 +73,20 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
 
 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
-		int cpu)
+						     unsigned int cpu)
 {
 	struct blk_mq_tag_set *set = q->tag_set;
 
 	return q->queue_hw_ctx[set->map[0].mq_map[cpu]];
 }
 
+static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
+							  unsigned int hctx_type,
+							  unsigned int cpu)
+{
+	return blk_mq_map_queue(q, cpu);
+}
+
 /*
  * sysfs helpers
  */