[WATCHDOG] Pre-Timeout flags

Some watchdog timers support the concept of a "pretimeout" which
occurs some time before the real timeout.  The pretimeout can
be delivered via an interrupt or NMI and can be used to panic
the system when it occurs (so you get useful information instead
of a blind reboot).

Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@osdl.org>