m68knommu: merge common ColdFire QSPI platform setup code

The ColdFire QSPI is common to quite a few ColdFire CPUs. No need to duplicate
its platform setup code for every CPU family member that has it. Merge all the
setup code into a single shared file.

This also results in few platforms no longer needing any local platform
setup code. In those cases remove the empty devices array and initcall
code as well.

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