dmaengine: sudmac: Include linux/err.h

linux/err.h isn't implicitly included by the current headers on all
platforms, resulting in compilation failures due to implicit
declarations of IS_ERR and PTR_ERR. Fix this by including linux/err.h.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/sh/sudmac.c b/drivers/dma/sh/sudmac.c
index b5b7e54..3ce1039 100644
--- a/drivers/dma/sh/sudmac.c
+++ b/drivers/dma/sh/sudmac.c
@@ -15,6 +15,7 @@
  */
 
 #include <linux/dmaengine.h>
+#include <linux/err.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>