hw/sparc64: Create VGA device only if it has really been requested

The sun4u/sun4v machine currently always creates a VGA device, even if
the user started QEMU with "-nodefaults" or "-vga none". That's likely
not what the users expect in this case, so add a check whether the VGA
adapter has really been requested.

Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

hw/sparc64/sun4u.c

@@ -596,7 +596,15 @@ static void sun4uv_init(MemoryRegion *address_space_mem,
     qdev_connect_gpio_out_named(DEVICE(ebus), "isa-irq", 4,
         qdev_get_gpio_in_named(DEVICE(sabre), "pbm-irq", OBIO_SER_IRQ));
 
-    pci_dev = pci_create_simple(pci_busA, PCI_DEVFN(2, 0), "VGA");
+    switch (vga_interface_type) {
+    case VGA_STD:
+        pci_create_simple(pci_busA, PCI_DEVFN(2, 0), "VGA");
+        break;
+    case VGA_NONE:
+        break;
+    default:
+        abort();   /* Should not happen - types are checked in vl.c already */
+    }
 
     memset(&macaddr, 0, sizeof(MACAddr));
     onboard_nic = false;