updateInterface: enable hot-add nic on arm64

For now, update interface in agent will fail when hot-add
nic to a running containers on arm64 as rescan pci bus will
occur between uf and bf of shpc hotplug interrupt handling.

Another problem is that the rootBusPath will be
"/devices/platform/4010000000.pcie/pci0000:00" on arm64.

To enable hot-add nic on arm64, rootBusPath should be changed here
and shpc hotplug should be disabled in guest kernel.

This patch just change rootBusPath.

Fixes: kata-containers#544
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>

device.go

@@ -35,8 +35,7 @@ const (
 )
 
 const (
-	rootBusPath = "/devices/pci0000:00"
-	pciBusMode  = 0220
+	pciBusMode = 0220
 )
 
 var (

device_amd64.go

@@ -0,0 +1,12 @@
+//
+// Copyright (c) 2019 Intel Corporation
+// Copyright (c) 2019 ARM Limited
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package main
+
+const (
+	rootBusPath = "/devices/pci0000:00"
+)

device_arm64.go

@@ -0,0 +1,9 @@
+//
+// Copyright (c) 2019 ARM Limited
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package main
+
+const rootBusPath = "/devices/platform/4010000000.pcie/pci0000:00"

device_ppc64le.go

@@ -0,0 +1,12 @@
+//
+// Copyright (c) 2019 Intel Corporation
+// Copyright (c) 2019 ARM Limited
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package main
+
+const (
+	rootBusPath = "/devices/pci0000:00"
+)

device_s390x.go

@@ -0,0 +1,12 @@
+//
+// Copyright (c) 2019 Intel Corporation
+// Copyright (c) 2019 ARM Limited
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package main
+
+const (
+	rootBusPath = "/devices/pci0000:00"
+)