m68knommu: add support for Coldfire 547x/548x interrupt controller

The Coldfire MCF547x/MCF548x have the same interrupt controller as
the MCF528x e.g., but only one, not two as in the MCF528x.  Modify
intc-2.c to support only one interrupt controller if MCFICM_INTC1 is
not defined.

Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>