Force this on for all ports. We have a few common models that can
be used, so make them generally available. If the port doesn't use
any hardware (the default), then behavior is unchanged.
This file is quite large and is getting unmanageable. Split it apart
to follow aclocal best practices by putting one-macro-per-file. There
shouldn't be any real functional changes here as can be seen in the
configure script regens.