PCI: build resource code for M68K architecture

The ColdFire M54xx family of CPU cores (supported by the m68k arch code)
have PCI bus hardware. We want to be able to use this and will need the
setup-bus.c and setup-irq.c helper functions. So when CONFIG_M68K is
enabled add them to the objs build list.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>