KVM: PPC: Pass program interrupt flags to the guest

When we need to reinject a program interrupt into the guest, we also need to
reinject the corresponding flags into the guest.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Avi Kivity <avi@redhat.com>