hw/pci/pci_host: Introduce PCI_HOST_BYPASS_IOMMU macro

Introduce a macro to avoid copy and pasting strings which can easily
cause typos.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20230630073720.21297-5-shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c
index dfd185b..7af8afd 100644
--- a/hw/pci/pci_host.c
+++ b/hw/pci/pci_host.c
@@ -232,7 +232,7 @@
 static Property pci_host_properties_common[] = {
     DEFINE_PROP_BOOL("x-config-reg-migration-enabled", PCIHostState,
                      mig_enabled, true),
-    DEFINE_PROP_BOOL("bypass-iommu", PCIHostState, bypass_iommu, false),
+    DEFINE_PROP_BOOL(PCI_HOST_BYPASS_IOMMU, PCIHostState, bypass_iommu, false),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/pci/pci_host.h b/include/hw/pci/pci_host.h
index c6f4eb4..e52d8ec 100644
--- a/include/hw/pci/pci_host.h
+++ b/include/hw/pci/pci_host.h
@@ -31,6 +31,8 @@
 #include "hw/sysbus.h"
 #include "qom/object.h"
 
+#define PCI_HOST_BYPASS_IOMMU "bypass-iommu"
+
 #define TYPE_PCI_HOST_BRIDGE "pci-host-bridge"
 OBJECT_DECLARE_TYPE(PCIHostState, PCIHostBridgeClass, PCI_HOST_BRIDGE)