for the i82596 PORT access interface, from the documentation
for that chip. These help clarify writes to the SYSBUS
part of the SCP, and PORT usage by i82596-aware drivers.
* Abolish C structures to access chip data-structures; instead use macros
that take indices and offsets relative to the bus handle representing
the chip's resources.
* Include the old version of this file wholesale, until all drivers
have been updated to use the MI 82586 code.
fredette