PCI: Always build setup-bus when PCI is enabled

CONFIG_HOTPLUG is being removed so setup-bus always needs to be built
as part of PCI.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>