[RFA] NEWS: Announce ppc-lynx178 support.

[Joel Brobecker]

> > gdb/ChangeLog:
> > 
> >         * NEWS: Add entry announcing ppc-lynx178 support.
> > 
> > OK to apply?
> 
> Yes, of course.  I think such changes should be treated as obvious.

OK, I will treat such updates as obvious in the future.
Patch now checked in.

Thanks,
-- 
Joel