clock: z_clock_device_ctrl -> sys_clock_device_ctrl
clock: z_clock_device_ctrl -> sys_clock_device_ctrl

Do not use z_ for internal APIs, z_ is for private APIs within one
subsystem only.

Signed-off-by: Anas Nashif <0d9952ec84ac43c159f6b7e7ed99a9080c00dd6e@intel.com>

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