I think I'd like to re-arrange the way that devices attach to the
VME bus in sparc configuration files.

Now we have two pseudo busses: `vmes' and `vmel' (for 16 and 32 bit data
access). The vme address space used by a device is present only
implicitly in the `addr' attribute, .e.g.

	cgtwo0  at vmes0 addr 0xff400000 level 4 vect 0xa8

where 0xff400000 implies the use 24 bit address mode.

Instead I want to have just one `vme' bus and define to more attributes,
`aspace' and `dspace', and leave the encoding and/or construction of
address mappings up to the vme bus code.

The example above would end up looking like:

        cgtwo0  at vme0 addr 0x400000 level 4 vect 0xa8 aspace 24 dspace 16


This would iron out the "kitchen sink" code obio.c and also make support for
VME on sun4m machines look less contorted.

Comments?

-pk