This firewall was not ported to RTEMS and is just dead code which may
make trouble during FreeBSD baseline updates. It also increased the
compile-time of the library for nothing.
Update #3472.
This adds two new buildset configurations: One that leaves out as much
features as possible and one that enables all features. For the default
configuration WiFi support is now disabled.
To disable IPv6 for the minimal configuration, all -DINET6 are
eliminated in libbsd.py. They are now replaced by a #ifdef that checks
for RTEMS_BSD_MODULE_NETINET6 instead.
Close#3351.
