powerpc/32: Remove Mac-on-Linux/rtlinux hooks

The symbols exported for use by MOL/rtlinux aren't getting CRCs and I
was about to fix that. But MOL is dead upstream, and the latest work on
it was to make it use KVM instead of its own kernel module. So remove
them instead.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>