Staging: One Laptop Per Child: fix SPDX-License-Identifier issue

Add SPDX-License-Identifier to the source files.
Remove redundant, old license.
Signed-off-by: Arkadiusz Lis <areklis909@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/olpc_dcon/olpc_dcon.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Mainly by David Woodhouse, somewhat modified by Jordan Crouse
  *
@@ -5,10 +6,6 @@
  * Copyright © 2006-2007  Advanced Micro Devices, Inc.
  * Copyright © 2009       VIA Technology, Inc.
  * Copyright (c) 2010-2011  Andres Salomon <dilinger@queued.net>
- *
- * This program is free software.  You can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

drivers/staging/olpc_dcon/olpc_dcon_xo_1.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Mainly by David Woodhouse, somewhat modified by Jordan Crouse
  *
@@ -5,10 +6,6 @@
  * Copyright © 2006-2007  Advanced Micro Devices, Inc.
  * Copyright © 2009       VIA Technology, Inc.
  * Copyright (c) 2010  Andres Salomon <dilinger@queued.net>
- *
- * This program is free software.  You can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

drivers/staging/olpc_dcon/olpc_dcon_xo_1_5.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2009,2010       One Laptop per Child
- *
- * This program is free software.  You can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt