Updated pci/if_* attach patches

I have made the following updates and these should be the versions that
will be committed (modulo any bugs people may find).

* Move bus_setup_intr to after ether_ifattach.  This removes the need for
any locking in *_attach because interrupts, even if shared, will not be
delivered until *_intr is hooked.

* Add bus_child_present check to calls to *_stop in the detach method for
devices that have children (i.e. miibus).

If you have one of these ethernet cards, please test the patches found at:
    http://www.root.org/~nate/freebsd/if-diffs/

Thanks,
Nate