Add device/dummy

device/buffer_list.h

@@ -17,6 +17,7 @@ typedef struct buffer_list_s {
 
   union {
     struct buffer_list_v4l2_s *v4l2;
+    struct buffer_list_dummy_s *dummy;
   };
 
   unsigned fmt_width, fmt_height, fmt_format, fmt_bytesperline, fmt_interval_us;