treewide: Add SPDX license identifier for more missed files

Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have MODULE_LICENCE("GPL*") inside which was used in the initial
   scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

drivers/watchdog/alim7101_wdt.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *	ALi M7101 PMU Computer Watchdog Timer driver
  *

drivers/watchdog/cpwd.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* cpwd.c - driver implementation for hardware watchdog
  * timers found on Sun Microsystems CP1400 and CP1500 boards.
  *

drivers/watchdog/diag288_wdt.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Watchdog driver for z/VM and LPAR using the diag 288 interface.
  *

drivers/watchdog/pcwd.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * PC Watchdog Driver
  * by Ken Hollis (khollis@bitgate.com)

drivers/watchdog/pika_wdt.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * PIKA FPGA based Watchdog Timer
  *

drivers/watchdog/riowd.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* riowd.c - driver for hw watchdog inside Super I/O of RIO
  *
  * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)