Enable ethernet on MacOS X even though slirp seems to have some small

problems on big endian systems. IOW, Basilisk II can hang there. I also
noticed that on Linux/ppc so that's probably not MacOS X specific, assuming
the same problem. ==> A packet arrives but Basilisk II can't seem to trigger
an interrupt (need to try sheep_net/tun in linux to make sure)

BasiliskII/src/Unix/configure.ac

@@ -474,6 +474,7 @@ irix*)
   CFLAGS="$ocflags"
   ;;
 darwin*)
+  ETHERSRC=ether_unix.cpp
   if [[ "x$ac_cv_framework_IOKit" = "xyes" ]]; then
     EXTRASYSSRCS="../MacOSX/sys_darwin.cpp"
   fi