KVM: PPC: Book3S_32 MMU debug compile fixes

Due to previous changes, the Book3S_32 guest MMU code didn't compile properly
when enabling debugging.

This patch repairs the broken code paths, making it possible to define DEBUG_MMU
and friends again.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>