DLINK 570 and if_dc support

["Peter Galbavy" <peter.galbavy@knowledge.com>]

This is an informational, but also a request.

We have a number of the DLINK-570 four port cards. The if_de driver is
really really bad for throughput, so a quick bit of hacking on current to
remove some ifdef's etc. has the card working very well with the if_dc
driver.

The steps are:

1. Remove the #if 0 ... #endif around the bit that allows the
 PCI_VENDOR_DEC, PCI_PRODUCT_DEC_21142 } to be matched in the probe routine.

2. The probe routine needs to return > 1 to be chosen over the if_de
driver - I just changed it to return 2.

3. The "nyphyter" PHYs needs to be config into the kernel else the lights
don't work with the ukphy driver.

I would have supplied patches but my sources are remote just now. If Jason
and Theo are happy, I can commit these changes directly later this weekend.

The throughput went from 50k/s to 6.5M/s (yes K to M).

Peter