gmp-4.2.4 on coldfire

[Torbjorn Granlund]

The right way to support a new CPU is:

* Make config.guess recognize it, using the various methods used therein.

* Teach config.sub any new cpu names, analogously with how existing cpu
  names are handled.

* Update configure.in to configure for the new cpu name.

Testing cpp predefines is not robust, and not how the GNU configure
system is supposed to work.

I don't know the coldfire is similar enough to 68k to put it under the
M68K_PATTERN (defined in acinclude.m4), or if it should be configured as
a completely separate cpu family.

-- 
Torbjörn