m68knommu: map ColdFire interrupts to correct masking bits

The older simple ColdFire interrupt controller has no one-to-one mapping
of interrupt numbers to bits in the interrupt mask register. Create a
mapping array that each ColdFire CPU type can populate with its available
interrupts and the bits that each use in the interrupt mask register.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>