fixup_pci: Remove unused attach DEVMETHOD

The probe routine always fails, so the attach routine is unused.
However, this weird driver is really a quirk system for PCI and should
be turned into PCI quirks instead.  The Natoma quirk is also broken as
it should be doing a runtime check either on mp_ncpus (or more likely
to see if it is using APIC) instead of #ifdef.

Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D47219

(cherry picked from commit 1cddce89ce30570d554120af864d23c554cd5d18)

sys/dev/pci/fixup_pci.c

@@ -56,7 +56,6 @@ static void	fixc1_nforce2(device_t dev);
 static device_method_t fixup_pci_methods[] = {
     /* Device interface */
     DEVMETHOD(device_probe,		fixup_pci_probe),
-    DEVMETHOD(device_attach,		bus_generic_attach),
     { 0, 0 }
 };