watchdog: keembay: Update pretimeout to zero in the TH ISR

The pretimeout has to be updated to zero during the ISR of the
ThresHold interrupt. Else the TH interrupt would be triggerred for
every tick until the timeout.

Fixes: fa0f8d51 ("watchdog: Add watchdog driver for Intel Keembay Soc")
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Kris Pan <kris.pan@intel.com>
Signed-off-by: Shruthi Sanil <shruthi.sanil@intel.com>
Link: https://lore.kernel.org/r/20210517174953.19404-4-shruthi.sanil@intel.com


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