driver: timer: npcx_itim: Add timer initialization
driver: timer: npcx_itim: Add timer initialization

The init responsibility moves to the drivers themselves. The npcx itim
initialize doesn't work now. This adds timer initialization for npcx
itim to fix it.

Signed-off-by: Wealian Liao <3fcda8e31b39800ae4b5099fe537977bd2d284f1@nuvoton.com>

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