q35: use macro for MCFG property name

Useful to make it accessible through QOM.
Reviewed-by: NGerd Hoffmann <kraxel@redhat.com>
Tested-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Tested-by: NIgor Mammedov <imammedo@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/pci-host/q35.c

@@ -110,7 +110,7 @@ static void q35_host_get_pci_hole64_end(Object *obj, Visitor *v,
 }
 
 static Property mch_props[] = {
-    DEFINE_PROP_UINT64("MCFG", Q35PCIHost, parent_obj.base_addr,
+    DEFINE_PROP_UINT64(PCIE_HOST_MCFG_BASE, Q35PCIHost, parent_obj.base_addr,
                         MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT),
     DEFINE_PROP_SIZE(PCI_HOST_PROP_PCI_HOLE64_SIZE, Q35PCIHost,
                      mch.pci_hole64_size, DEFAULT_PCI_HOLE64_SIZE),

include/hw/pci/pcie_host.h

@@ -28,6 +28,8 @@
 #define PCIE_HOST_BRIDGE(obj) \
     OBJECT_CHECK(PCIExpressHost, (obj), TYPE_PCIE_HOST_BRIDGE)
 
+#define PCIE_HOST_MCFG_BASE "MCFG"
+
 /* pcie_host::base_addr == PCIE_BASE_ADDR_UNMAPPED when it isn't mapped. */
 #define PCIE_BASE_ADDR_UNMAPPED  ((hwaddr)-1ULL)