boards: arm: nucleo_u575zi_q: Add watchdog0 alias to dts file
boards: arm: nucleo_u575zi_q: Add watchdog0 alias to dts file

Add watchdog0 alias to dts file for correctly compiling
samples/drivers/watchdog sample.

Signed-off-by: TOKITA Hiroshi <501187a43400793219de4d849513395616209606@fujitsu.com>

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