mtd: introduce mtd_suspend interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index ad487fc..c5e556a 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -307,7 +307,7 @@
 static int part_suspend(struct mtd_info *mtd)
 {
 	struct mtd_part *part = PART(mtd);
-	return part->master->suspend(part->master);
+	return mtd_suspend(part->master);
 }
 
 static void part_resume(struct mtd_info *mtd)