I have re-oragnized the code supporting ISA PnP to "behave" like the
other NetBSD drivers.

I guess this make it's easier to use the code on other platforms also
empoly ISA bus.

It's available at

  http://hercules.secc.fju.edu.tw/~shawn/ISA_PnP_NetBSD.Jun21.tar.gz

BTW, it also incorporate the fix that Sujal Patel mentioned early.