Dual link does not mean two cables. DVI-D cables come with either dual link or single link connectors but both of them still only require one DVI port. The DVI-D port on your RX 470 will work fine with a dual link DVI-D cable for 144Hz. The monitor will most likely have a compatible cable in the box.
The only time you GPU only having 1 DVI port will become a problem is if you get two monitors and both of them are DVI. Even then it isn't that much of a problem since a DisplayPort to DVI adapter would get the job done.