watchdog: xilinx: Move no_timeout to probe function

no_timeout should be local variable because it is used
only in probe function.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>