Support the new PV EOI flag in kvm - it recently got merged
into kvm.git. Set by default with -cpu kvm.
Set for -cpu qemu by adding +kvm_pv_eoi.
Clear by adding -kvm_pv_eoi to -cpu option.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>