kvm: get/set PV EOI MSR

Support get/set of new PV EOI MSR, for migration.
Add an optional section for MSR value - send it
out in case MSR was changed from the default value (0).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 60f9e97..0677502 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -699,6 +699,7 @@
     uint64_t system_time_msr;
     uint64_t wall_clock_msr;
     uint64_t async_pf_en_msr;
+    uint64_t pv_eoi_en_msr;
 
     uint64_t tsc;
     uint64_t tsc_deadline;