PPC: Newworld: Add uninorth token register

Mac OS X expects the uninorth control register set to contain one
register that always reads back what it writes in. Expose that.

This is just a temporary hack. Eventually, we want to expose the
uninorth (/uni-n in device tree) as a separate QOM device.

Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: Newworld: Add second uninorth control register set

Mac OS X requires a second uninorth register set to be mapped a few
bytes above the first one. Let's just expose it to make it happy.

Signed-off-by: Alexander Graf <agraf@suse.de>