spi: Add GPL-2.0+ SPDX-License-Identifier for missing files

Added GPL-2.0+ SPDX-License-Identifier for missed spi
source files.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>

drivers/spi/altera_spi.c

@@ -5,7 +5,7 @@
  * Copyright (c) 2005-2008 Analog Devices Inc.
  * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
  *
- * Licensed under the GPL-2 or later.
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 #include <common.h>
 #include <asm/io.h>

drivers/spi/bfin_spi.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2005-2010 Analog Devices Inc.
  *
- * Licensed under the GPL-2 or later.
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 
 /*#define DEBUG*/

drivers/spi/oc_tiny_spi.c

@@ -7,7 +7,7 @@
  * Copyright (c) 2005-2008 Analog Devices Inc.
  * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
  *
- * Licensed under the GPL-2 or later.
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>

drivers/spi/xilinx_spi.c

@@ -9,7 +9,7 @@
  * Copyright (c) 2010 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
  * Copyright (c) 2012 Stephan Linz <linz@li-pro.net>
  *
- * Licensed under the GPL-2 or later.
+ * SPDX-License-Identifier:	GPL-2.0+
  *
  * [0]: http://www.xilinx.com/support/documentation
  *

drivers/spi/xilinx_spi.h

@@ -9,7 +9,7 @@
  * Copyright (c) 2010 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
  * Copyright (c) 2012 Stephan Linz <linz@li-pro.net>
  *
- * Licensed under the GPL-2 or later.
+ * SPDX-License-Identifier:	GPL-2.0+
  *
  * [0]: http://www.xilinx.com/support/documentation
  *