block: Expose kblock_schedule_delayed_work()

This function is exported in blk-core.c to be used in other modules
but it's definition in h file is missing.

Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
(cherry picked from commit 87c7500d26ddddf2851bbe65190f5d8970b0346d)

Change-Id: I94a1603c345db9a92237ff6696bf29e6afbe69b7
Signed-off-by: Sudhir Sharma <sudsha@codeaurora.org>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index a19d374..e76b0ae 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1167,6 +1167,8 @@
 
 struct work_struct;
 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
+int kblockd_schedule_delayed_work(struct request_queue *q,
+			struct delayed_work *dwork, unsigned long delay);
 
 #ifdef CONFIG_BLK_CGROUP
 /*