. use a structure for the tag instead of an integer constant,
. add bus_space_{peek,poke}_N() (and G/C `badaddr()'),
. fix a few drivers which have dependencies on the implementation.
deal with dynamic address modifier generation based on the CPU's
function code pins.
Also implement VMEbus slave mode for mvme147. (Not yet 100% working.)
These changes add support for:
o The MI VMEbus framework on both MVME147 and MVME167.
o Enhancements to the existing MD bus_space(9) implementation.
o Most of the bus_dma(9) API.
scw