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>
diff --git a/drivers/spi/bfin_spi.c b/drivers/spi/bfin_spi.c
index f7192c2..bb88f30 100644
--- a/drivers/spi/bfin_spi.c
+++ b/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*/