Move dev->subdev_fd to dev->v4l2.subdev_fd

device/device.h

@@ -33,13 +33,16 @@ typedef struct device_s {
   char *path;
   char bus_info[64];
   int fd;
-  int subdev_fd;
   bool allow_dma;
 
   device_hw_t *hw;
   buffer_list_t *capture_list;
   buffer_list_t *output_list;
 
+  struct {
+    int subdev_fd;
+  } v4l2;
+
   device_t *output_device;
   bool paused;
   bool decoder_started;