qmi_wwan: add ONDA MT689DC device ID (fwd)

Another QMI-speaking device by ZTE, re-branded by ONDA!

I'm connected ovr this device's QMI interface right now, so I can say I tested
it! :)

Note: a follow-up patch was posted to the linux-usb mailing list, to prevent
the option driver from binding to the device's QMI interface, making it
unusable.

Signed-off-by: Enrico Mioso <mrkiko.rs@gmail.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>