Cycles: Solve dependency between camera and object synchronization

IN theory object might depend on camera location (spatial adaptive subdivisions
for example) which became not possible to achieve after camera in volume support.

Should be no functional changes for artists.

intern/cycles/render/camera.h

@@ -116,6 +116,7 @@ public:
 	void update();
 
 	void device_update(Device *device, DeviceScene *dscene, Scene *scene);
+	void device_update_volume(Device *device, DeviceScene *dscene, Scene *scene);
 	void device_free(Device *device, DeviceScene *dscene);
 
 	bool modified(const Camera& cam);