I've tracked down the core issue giving me the oops wrt pmac_zilog.

When you have two serial drivers, (e.g. 8250 and PMAC_ZILOG) they both say

"I want to reserve X ports starting with major TTY_MAJOR and minor 64".

By the time pmac_zilog gets there, the ports it requests are already
reserved.  Unfortunately, init_pmz() doesn't check for pmz_register()
failure, and so it merrily goes on to register the half-initialized
pmac_zilog driver with the power management subsystem.

This path provides a proper failure path.

Also: 

Restore ppc configs now that I know people use AT Keyboards on CHRP and PReP
machines, and the zilog driver is no longer Oops'ing.
Signed-off-by: David Eger <eger@havoc.gtf.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>