main change:
* greatly improve per-NIC probe diagnostic output. Similar to other
net drivers, print out MAC address, PHY info, and various hardware and
software flags that may be relevant.
other changes:
* similar to other net drivers, only print the initial version message
when we have found at least one board.
* don't bother to print error message when pci_enable_device() fails,
it will do so for us.
* use dev_printk() rather than printk() in nv_probe(). This gives
use a standardized output similar to the rest of the kernel, and
eliminates the need to manually print out PCI bus id.