still building soft-fp on ppclinux

[Roland McGrath]

> also config.make still comes up with 'sysdeps/powerpc/soft-fp' in the list
> of config-sysdirs even though it also shows...
> 
> completely-soft =

I think this is fine in principle.  It just makes the code available so
that binaries compiled on a soft-fp will run with a libc you build.
But if that was not the intention, these changes are definitely all wrong.
They're still pretty buggy for that too.