Remove the ofb driver. I'm not interested in trying to make this work.
It should be replaced with the genfb driver, which I have added,
commented out because that driver needs work before it will function on
ofppc. (it's too panic-happy, and ofppc needs a working autoconf.c)
Change the way we do isa_inb/outb. The new way is a slightly nastier
hack, but won't run afoul of the other isa drivers as much.
Fix ofw_consinit.c to remove the dependency on ofb.
de8e7fde3e