drivers: watchdog: Fix callback call on STM32 WWDG enable
drivers: watchdog: Fix callback call on STM32 WWDG enable

When using the EWIF it is a good idea to clear it before enabling the
watchdog. Otherwise, the watchdog callback will be called upon watchdog
enable if EWIF is enabled. This patch fixes this case.

Signed-off-by: Ioannis Konstantelias <040e5d416c788b2fd8261c18321a5c78629754f5@gmail.com>

nashif/zephyr,galak/zephyr,nashif/zephyr,Vudentz/zephyr,finikorg/zephyr,Vudentz/zephyr,Vudentz/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr,nashif/zephyr,galak/zephyr,galak/zephyr,galak/zephyr,Vudentz/zephyr,nashif/zephyr,galak/zephyr