[PATCH] i8xx_tco.c: arm watchdog only when started

i8xx_tco.c v0.08: only "arm" the watchdog when the watchdog has been
started.  (Kernel Bug 4251: system reset when battery is read and i8xx_tco
driver loaded)

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>