xbox: Fixup pcspk_init with new prototype

See the following commits for more info:
- audio: rework pcspk_init()
- isa: Convert uses of isa_create() with Coccinelle
- audio: create pcspk device early

hw/xbox/xbox.c

@@ -374,7 +374,7 @@ void xbox_init_common(MachineState *machine,
 
     i8257_dma_init(isa_bus, 0);
 
-    pcspk_init(isa_bus, pit);
+    pcspk_init(pcms->pcspk, isa_bus, pit);
 
     PCIDevice *dev = pci_create_simple(pci_bus, PCI_DEVFN(9, 0), "piix3-ide");
     pci_ide_create_devs(dev);