Add watchdogd

"/sbin/watchdogd <interval> <margin>" will open /dev/watchdog, try
to set the timeout to <interval>+<margin> then write to it every
<interval> seconds to reset the watchdog.

Change-Id: I15571980cdb868ec19f20e80bf8274b32107d36d
diff --git a/init/watchdogd.h b/init/watchdogd.h
new file mode 100644
index 0000000..8b48ab8
--- /dev/null
+++ b/init/watchdogd.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _INIT_WATCHDOGD_H_
+#define _INIT_WATCHDOGD_H_
+
+int watchdogd_main(int argc, char **argv);
+
+#endif