video: Use cache-alignment in video_sync()

Sometimes the frame buffer is not a multiple of the cache line size.
Adjust the cache-flushing code to avoid cache warnings/errors in this
case.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/video/video-uclass.c

@@ -117,7 +117,8 @@ void video_sync(struct udevice *vid)
 
 	if (priv->flush_dcache) {
 		flush_dcache_range((ulong)priv->fb,
-				   (ulong)priv->fb + priv->fb_size);
+				   ALIGN((ulong)priv->fb + priv->fb_size,
+					 CONFIG_SYS_CACHELINE_SIZE));
 	}
 #elif defined(CONFIG_VIDEO_SANDBOX_SDL)
 	struct video_priv *priv = dev_get_uclass_priv(vid);