block: move block-related definitions out of fs.h

Move most of the block related definition out of fs.h into more suitable
headers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/reiserfs/procfs.c b/fs/reiserfs/procfs.c
index ff33651..155b828 100644
--- a/fs/reiserfs/procfs.c
+++ b/fs/reiserfs/procfs.c
@@ -15,6 +15,7 @@
 #include "reiserfs.h"
 #include <linux/init.h>
 #include <linux/proc_fs.h>
+#include <linux/blkdev.h>
 
 /*
  * LOCKING: