kconfig: Mark dt_{int,hex,str}_val as deprecated
kconfig: Mark dt_{int,hex,str}_val as deprecated

As we work on removing the .conf file that is generated by the dt
scripts, mark dt_{int,hex,str}_val functions as deprecated.

Signed-off-by: Kumar Gala <a5e5248af4cd4f0ed8c515f61d40a6e2db46a66e@linaro.org>

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