spapr: define SPAPR_COMPAT_2_3

Don't add the pseries-2.3 machine yet, but define the corresponding
SPAPR_COMPAT macro to make sure both pseries-2.2 and pseries-2.1 will
inherit HW_COMPAT_2_3.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/ppc/spapr.c

@@ -1815,7 +1815,11 @@ static const TypeInfo spapr_machine_info = {
     },
 };
 
+#define SPAPR_COMPAT_2_3 \
+        HW_COMPAT_2_3
+
 #define SPAPR_COMPAT_2_2 \
+        SPAPR_COMPAT_2_3 \
         HW_COMPAT_2_2 \
         {\
             .driver   = TYPE_SPAPR_PCI_HOST_BRIDGE,\