V4L/DVB (13648): soc-camera: add a private field to struct soc_camera_link

Up to now, if a client driver needed platform data apart from those contained
in struct soc_camera_link, it had to embed the struct into its own object. This
makes the use of such a driver in configurations other than soc-camera
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

include/media/soc_camera.h

@@ -104,6 +104,8 @@ struct soc_camera_link {
 	int i2c_adapter_id;
 	struct i2c_board_info *board_info;
 	const char *module_name;
+	void *priv;
+
 	/*
 	 * For non-I2C devices platform platform has to provide methods to
 	 * add a device to the system and to remove