xen/pci: Make xen-pcifront be dependent on XEN_XENBUS_FRONTEND

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 5b1630e..a9523fd 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -45,6 +45,7 @@
         depends on PCI && X86 && XEN
         select HOTPLUG
         select PCI_XEN
+	select XEN_XENBUS_FRONTEND
         default y
         help
           The PCI device frontend driver allows the kernel to import arbitrary