md: move offset, daemon_sleep and chunksize out of bitmap structure

... and into bitmap_info.  These are all configuration parameters
that need to be set before the bitmap is created.

Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 50e62ef..4b07e0a 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -291,6 +291,9 @@
 							 * eventually be settable by sysfs.
 							 */
 		struct mutex		mutex;
+		unsigned long		chunksize;
+		unsigned long		daemon_sleep; /* how many seconds between updates? */
+		unsigned long		max_write_behind; /* write-behind mode */
 	} bitmap_info;
 
 	struct list_head		all_mddevs;