It seems that X86 architectures in general need the setup-bus.o
not just those with HOTPLUG.  This avoids the following error on
X86_NUMAQ and x86_64:

    arch/i386/pci/built-in.o(.init.text+0x15a6): In function `pcibios_init':
    : undefined reference to `pci_assign_unassigned_resources'
Signed-off-by: NAndy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>