Ovfm/Xen: add a Vendor Hardware device path GUID for the XenBus root

On non-PCI Xen guests (such as ARM), the XenBus root is not a PCI
device but an abstract 'platform' device. Add a dedicated Vendor
Hardware device path GUID to identify this node.

Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16978 6f19259b-4bc3-4df7-8a09-765794883524

OvmfPkg/Include/Guid/XenBusRootDevice.h

@@ -0,0 +1,24 @@
+/** @file
+  GUID to be used to identify the XenBus root node on non-PCI Xen guests
+
+  Copyright (C) 2015, Linaro Ltd.
+
+  This program and the accompanying materials are licensed and made available
+  under the terms and conditions of the BSD License that accompanies this
+  distribution. The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php.
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#ifndef __XENBUS_ROOT_DEVICE_H__
+#define __XENBUS_ROOT_DEVICE_H__
+
+#define XENBUS_ROOT_DEVICE_GUID \
+{0xa732241f, 0x383d, 0x4d9c, {0x8a, 0xe1, 0x8e, 0x09, 0x83, 0x75, 0x89, 0xd7}}
+
+extern EFI_GUID gXenBusRootDeviceGuid;
+
+#endif