the resource table to locate children. The 'at ppbus?' can go again.
Remove a few #if Nxxx > 0' type things, config arranges this for us.
Move the newbus method glue next to the DRIVER_MODULE() stuff so we
don't need extra prototypes.
Don't set device descriptions until after the possibility of the probe
returning an error.
Remove all cdevsw_add() calls, all the drivers that did this also use
make_dev() correctly, so it's not required.
A couple of other minor nits.
