pci-swiotlb-xen: call pci_request_acs only ifdef CONFIG_PCI

Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

arch/x86/xen/pci-swiotlb-xen.c

@@ -75,8 +75,10 @@ void __init pci_xen_swiotlb_init(void)
 		xen_swiotlb_init(1, true /* early */);
 		dma_ops = &xen_swiotlb_dma_ops;
 
+#ifdef CONFIG_PCI
 		/* Make sure ACS will be enabled */
 		pci_request_acs();
+#endif
 	}
 }
 
@@ -92,8 +94,10 @@ int pci_xen_swiotlb_init_late(void)
 		return rc;
 
 	dma_ops = &xen_swiotlb_dma_ops;
+#ifdef CONFIG_PCI
 	/* Make sure ACS will be enabled */
 	pci_request_acs();
+#endif
 
 	return 0;
 }