PPC fix from Alex Graf: "It contains an important bug fix which
can lead to guest freezes when using PAPR guests with PR KVM."
* 'for-upstream-master' of git://github.com/agraf/linux-2.6:
powerpc/kvm: Fix "PR" KVM implementation of H_CEDE
Signed-off-by: Avi Kivity <avi@redhat.com>