Hi,
I made a 4-layer PCB with the cy7c68013a chip and it was fully functionnal. I did not make any impedance control and it worked very well. I am currently designing a 2-layer PCB with the same chip and it should work fine. I suggest to minimize the length of the differential traces to the usb connector. The lengths should be equal. You can also try to respect the impedances (Z0 and Zdiff) of the USB traces, but I didn't take care of this and it work fine. The rest of your PCB will work at 48MHz maximum, which is not fast enough to consider impedance control (In my opinion).
Max