intvid didn't find the frame buffer on his PB 170 in NetBSD 1.5. This is
because the PowerBook 140/145+145B/170 entries in intvid_info[] were
entered into the table directly from the corresponding hardware tech
notes. Unfortunately, the actual frame buffer is mapped at an offset
of 32 KB from the base of the region (at least when in 32-bit mode).
Since all 4 of these systems have identical video configurations, I'm
updating the rest to match.
91087ff57e