prep: add ppc-parity write method Add ppc-parity mmio write method to avoid NULL pointer dereference issue. Reported-by: Lei Sun <slei.casper@gmail.com> Acked-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> Reviewed-by: Li Qiang <liq3ea@gmail.com> Message-Id: <20200811114133.672647-5-ppandit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>