hw/ppc/spapr: Add support for "-vga cirrus"

The cirrus VGA card has been enabled in the PPC builds with
commit 29f9cef ("ppc: Include vga cirrus card into
the compiling process") last year. It also works on the pseries
machine, even SLOF contains support for this card, so we can
also support this for the "-vga" parameter here.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/ppc/spapr.c

@@ -1715,6 +1715,7 @@ static bool spapr_vga_init(PCIBus *pci_bus, Error **errp)
         return true;
     case VGA_STD:
     case VGA_VIRTIO:
+    case VGA_CIRRUS:
         return pci_vga_init(pci_bus) != NULL;
     default:
         error_setg(errp,