sys/x86: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

3 files changed, 8 insertions, 2 deletions

diff --git a/sys/x86/xen/hvm.c b/sys/x86/xen/hvm.c
index e10659e64ad1..4c62cf076c5c 100644
--- a/sys/x86/xen/hvm.c
+++ b/sys/x86/xen/hvm.c
@@ -1,4 +1,6 @@
-/*
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
  * Copyright (c) 2008, 2013 Citrix Systems, Inc.
  * Copyright (c) 2012 Spectra Logic Corporation
  * All rights reserved.
diff --git a/sys/x86/xen/pv.c b/sys/x86/xen/pv.c
index 9ad9aa951f83..8af309301640 100644
--- a/sys/x86/xen/pv.c
+++ b/sys/x86/xen/pv.c
@@ -1,4 +1,6 @@
-/*
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-NetBSD
+ *
  * Copyright (c) 2004 Christian Limpach.
  * Copyright (c) 2004-2006,2008 Kip Macy
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
diff --git a/sys/x86/xen/pvcpu_enum.c b/sys/x86/xen/pvcpu_enum.c
index 5871b9d3c2c6..e11471ba3712 100644
--- a/sys/x86/xen/pvcpu_enum.c
+++ b/sys/x86/xen/pvcpu_enum.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
  * Copyright (c) 2003 John Baldwin <jhb@FreeBSD.org>
  * Copyright (c) 2013 Roger Pau Monné <roger.pau@citrix.com>
  * All rights reserved.