boot/zephyr: feed watchdog at the start

Added call to the watchdog feed macro at the
MCUBoot's main() beginning.

Signed-off-by: Andrzej Puzdrowski <[email protected]>

Author: nvlsianpu

boot/zephyr/main.c

@@ -313,6 +313,8 @@ void main(void)
     int rc;
     fih_int fih_rc = FIH_FAILURE;
 
+    MCUBOOT_WATCHDOG_FEED();
+
     BOOT_LOG_INF("Starting bootloader");
 
     os_heap_init();