[media] v4l: vsp1: Fix vsp1_du_atomic_(begin|flush) declarations

The functions are void, make the declaration match the definition.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

include/media/vsp1.h

@@ -23,11 +23,11 @@ int vsp1_du_init(struct device *dev);
 int vsp1_du_setup_lif(struct device *dev, unsigned int width,
 		      unsigned int height);
 
-int vsp1_du_atomic_begin(struct device *dev);
+void vsp1_du_atomic_begin(struct device *dev);
 int vsp1_du_atomic_update(struct device *dev, unsigned int rpf, u32 pixelformat,
 			  unsigned int pitch, dma_addr_t mem[2],
 			  const struct v4l2_rect *src,
 			  const struct v4l2_rect *dst);
-int vsp1_du_atomic_flush(struct device *dev);
+void vsp1_du_atomic_flush(struct device *dev);
 
 #endif /* __MEDIA_VSP1_H__ */