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/maps/rbtx4939-flash.c b/drivers/mtd/maps/rbtx4939-flash.c
index bb7d204..5856aa2 100644
--- a/drivers/mtd/maps/rbtx4939-flash.c
+++ b/drivers/mtd/maps/rbtx4939-flash.c
@@ -120,7 +120,7 @@
 	struct rbtx4939_flash_info *info = platform_get_drvdata(dev);
 
 	if (info->mtd->suspend && info->mtd->resume)
-		if (info->mtd->suspend(info->mtd) == 0)
+		if (mtd_suspend(info->mtd) == 0)
 			info->mtd->resume(info->mtd);
 }
 #else