#49 patch for 3c597 EISA NIC

https://sourceforge.net/mailarchive/forum.php?thread_id=5660321&forum_id=6402

A submitted patch for the 3c597 can be found at the URL
above. Since EISA cards are rare and becoming extinct,
it is difficult to verify such submissions, so this
patch will not go into the distribution unless someone
can fix the code to autoprobe for the IO address (it's
hardwired in the code) and warrant that it works.