[patch] Set SER_HARDWIRE using autoconf

[Stan Shebs]

Andrew Cagney wrote:
> 
> FYI,
> 
> I've checked in the attached.  By default a target will be built with
> ser-tcp.o.  go32*-*-* is currently the only exception.

Cool!  Another nice simplification of the sources.  I vaguely remember
one or two other platforms that would choke on ser-tcp, for instance old
flavors of SVR3 wouldn't have sockets, but autoconfiscation ought
to be able to handle that just fine, assuming any such systems still
survive...

Stan