[media] si470x: add check to test if this is really a si470x

	}

	radio->v4l2_dev.release = si470x_usb_release;

	/*

	 * The si470x SiLabs reference design uses the same USB IDs as

	 * 'Thanko's Raremono' si4734 based receiver. So check here which we

	 * have: attempt to read the device ID from the si470x: the lower 12

	 * bits should be 0x0242 for the si470x.

	 *

	 * We use this check to determine which device we are dealing with.

	 */

	if (id->idVendor == 0x10c4 && id->idProduct == 0x818a) {

		retval = usb_control_msg(radio->usbdev,

				usb_rcvctrlpipe(radio->usbdev, 0),

				HID_REQ_GET_REPORT,

				USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,

				1, 2,

				radio->usb_buf, 3, 500);

		if (retval != 3 ||

		    (get_unaligned_be16(&radio->usb_buf[1]) & 0xfff) != 0x0242) {

			dev_info(&intf->dev, "this is not a si470x device.\n");

			retval = -ENODEV;

			goto err_urb;

		}

	}

	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);

	if (retval < 0) {

		dev_err(&intf->dev, "couldn't register v4l2_device\n");