watchdog: qcom: support pre-timeout when the bark irq is available

Use the bark interrupt as the pre-timeout notifier whenever this
interrupt is available.

By default, the pretimeout notification shall occur one second earlier
than the timeout.

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20190906205411.31666-2-jorge.ramirez-ortiz@linaro.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>