Time-out support

[hanusek]

Hello.
I have test code:

    let mut socket_rx = CANSocket::open("vcan0").unwrap();
    let socket_tx = CANSocket::open("vcan0").unwrap();

    while let Some(Ok(frame)) = socket_rx.next().await
    {
        println!("frame: {:?}", frame);
        socket_tx.write_frame(frame).unwrap().await.unwrap();
    }

but I have a problem. I would like a timeout.