* Use BUS_ADDR() where appropriate to encode I/O space and physical
address offset into a `bus_addr_t' value.
* Drop obio_bus_map() since it's now completely equivalent to bus_space_map()
* Use bus_space_map2() to map device space at a fixed virtual address.
* Remove the virtual address argument from sbus_sbus_addr()
laptops. There is currently something wrong with the interrupt
code but it does attach and sense a 16550a. (anyways the built
in modem is only a 14.4Kb and you'd really want to use a PCMCIA
modem to get faster dialup rates).