watchdog: iTCO_wdt: Set NO_REBOOT if the watchdog is not already running

Daniel reported that the commit 1ae3e78c ("watchdog: iTCO_wdt: No
need to stop the timer in probe") makes QEMU implementation of the iTCO
watchdog not to trigger reboot anymore when NO_REBOOT flag is initially
cleared using this option (in QEMU command line):

  -global ICH9-LPC.noreboot=false

The problem with the commit is that it left the unconditional setting of
NO_REBOOT that is not cleared anymore when the kernel keeps pinging the
watchdog (as opposed to the previous code that called iTCO_wdt_stop()
that cleared it).

Fix this so that we only set NO_REBOOT if the watchdog was not initially
running.

Fixes: 1ae3e78c ("watchdog: iTCO_wdt: No need to stop the timer in probe")
Reported-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20221028062750.45451-1-mika.westerberg@linux.intel.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>