spdx: The BSD-2-Clause-NetBSD identifier is obsolete, drop -NetBSD

The SPDX folks have obsoleted the BSD-2-Clause-NetBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with:		pfg
MFC After:		3 days
Sponsored by:		Netflix

sys/arm/include/_inttypes.h

@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-NetBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
  * All rights reserved.

sys/arm/include/_stdint.h

@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-NetBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2001, 2002 Mike Barcroft <mike@FreeBSD.org>
  * Copyright (c) 2001 The NetBSD Foundation, Inc.

sys/arm/include/bus_dma.h

@@ -1,7 +1,7 @@
 /*	$NetBSD: bus.h,v 1.11 2003/07/28 17:35:54 thorpej Exp $	*/
 
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-NetBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 1996, 1997, 1998, 2001 The NetBSD Foundation, Inc.
  * All rights reserved.

sys/arm/include/ucontext.h

@@ -1,7 +1,7 @@
 /*	$NetBSD: mcontext.h,v 1.4 2003/10/08 22:43:01 thorpej Exp $	*/
 
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-NetBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2001, 2002 The NetBSD Foundation, Inc.
  * All rights reserved.