A quick update on this problem. After days of beating my head on this issue I determined that the isp116x_udc_probe() function is never being called. That results in the device data structure never being assigned so the driver_register function fails. That was the easy part to figure out :). Where the actual probe function gets called, or should get called, eludes me. I have tried to configure this driver as a module and that failes too.
I found a thread in the blackfin mail-archive where someone seems to have ran into this exact same problem (using a NET2272 device). As near as I can tell, that has never been resolved either.
If someone smarter than me can offer some direction, it would be really appreciated. Thanks -Alex P.S. we need a crying icon