Reboot support for Phase5 PPC/68K boards: please test

[Ignatios Souvatzis <is%jocelyn.rhein.de@localhost>]

Hello,

those of you with P5PPC+68K boards who run NetBSD-current: please rebuild
your kernel after your next source update, and test wether rebooting works.

If your 68k CPU is a 040, it probably did not come up again. At least mine
didn't, and I've heard it from elsewhere.

I looked at what Linux/APUS does, and adapted to the NetBSD/Amiga(68k) kernel.
It works for me, but I want reports from people with 68060 companion CPUs, or
with Cyberstorm Mk III without PPC.

Regards,
        -is