hw/xen: Constify all Property

Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

hw/xen/xen-bus.c

@@ -1092,7 +1092,7 @@ unrealize:
     xen_device_unrealize(dev);
 }
 
-static Property xen_device_props[] = {
+static const Property xen_device_props[] = {
     DEFINE_PROP_UINT16("frontend-id", XenDevice, frontend_id,
                        DOMID_INVALID),
     DEFINE_PROP_END_OF_LIST()

hw/xen/xen_pt.c

@@ -931,7 +931,7 @@ static void xen_pt_unregister_device(PCIDevice *d)
     xen_pt_destroy(d);
 }
 
-static Property xen_pci_passthrough_properties[] = {
+static const Property xen_pci_passthrough_properties[] = {
     DEFINE_PROP_PCI_HOST_DEVADDR("hostaddr", XenPCIPassthroughState, hostaddr),
     DEFINE_PROP_BOOL("permissive", XenPCIPassthroughState, permissive, false),
     DEFINE_PROP_END_OF_LIST(),