drivers: wdog: Update CMSDK Wdog driver
drivers: wdog: Update CMSDK Wdog driver

The commit 0c2ef4ea3dbff2a7746dddd49df6fb0842209382 "drivers:
watchdog: Watchdog API redesign" introduced an API redesign for the
watchdog drivers compliant with Zephyr.

This patch updated the CMSDK Watchdog driver to be compliant with the
new API.

Signed-off-by: Vincenzo Frascino <3ace7bb34570a19a202c4c73ce7a798ea734bba6@linaro.org>

ldts/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,nashif/zephyr,explora26/zephyr,ldts/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,Vudentz/zephyr,finikorg/zephyr,Vudentz/zephyr,ldts/zephyr,explora26/zephyr,galak/zephyr,galak/zephyr,galak/zephyr,Vudentz/zephyr,punitvara/zephyr,punitvara/zephyr,nashif/zephyr,explora26/zephyr,galak/zephyr,punitvara/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,punitvara/zephyr,galak/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,Vudentz/zephyr,punitvara/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,nashif/zephyr