acpi: fix ACPI generation for pci bridges

Commit 8dcf525a
    acpi-build: append description for non-hotplug
appended description for all occupied non hotpluggable PCI slots.
However the bridge devices are already added to SSDT,
adding them again will create an incorrect SSDT table.

Fixed by skipping the pci bridge devices, marking them as 'system'.
Signed-off-by: NMarcel Apfelbaum <marcel.a@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/i386/acpi-build.c

@@ -841,7 +841,7 @@ static void build_pci_bus_end(PCIBus *bus, void *bus_state)
         pc = PCI_DEVICE_GET_CLASS(pdev);
         dc = DEVICE_GET_CLASS(pdev);
 
-        if (pc->class_id == PCI_CLASS_BRIDGE_ISA) {
+        if (pc->class_id == PCI_CLASS_BRIDGE_ISA || pc->is_bridge) {
             set_bit(slot, slot_device_system);
         }
 
@@ -882,7 +882,7 @@ static void build_pci_bus_end(PCIBus *bus, void *bus_state)
             memcpy(pcihp, ACPI_PCIVGA_AML, ACPI_PCIVGA_SIZEOF);
             patch_pcivga(i, pcihp);
         } else if (system) {
-            /* Nothing to do: system devices are in DSDT. */
+            /* Nothing to do: system devices are in DSDT or in SSDT above. */
         } else if (present) {
             void *pcihp = acpi_data_push(bus_table,
                                          ACPI_PCINOHP_SIZEOF);