s390/watchdog: add support for LPAR operation (diag288)

Add the LPAR variant of the diag 288 watchdog to the driver.
The only available action on timeout for LPAR is a PSW restart.

Signed-off-by: Philipp Hachtmann <phacht@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index daf9441..ac1f1de 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1304,6 +1304,8 @@
 	  provide a virtual watchdog timer to their guest that cause a
 	  user define Control Program command to be executed after a
 	  timeout.
+	  LPAR provides a very similar interface. This driver handles
+	  both.
 
 	  To compile this driver as a module, choose M here. The module
 	  will be called vmwatchdog.