Support for stop watchdog

Add interface to stop the currently running watchdog if any.
diff --git a/bin/ipmi_example.py b/bin/ipmi_example.py
index ba13b60..f8b921e 100755
--- a/bin/ipmi_example.py
+++ b/bin/ipmi_example.py
@@ -120,8 +120,12 @@
 	elif (cmd == "statewatchdog"):
 		intf = getWatchdog()
 		intf.start()
+	elif (cmd == "stopwatchdog"):
+		intf = getWatchdog()
+		intf.stop()
 	elif (cmd == "setwatchdog"):
 		count = int(sys.argv[2])
+		intf = getWatchdog()
 		intf.set(count)
 	else:
 		print "Unsupported command"