drivers: arcv2_timer0: rename overflow_cyc to overflow_cycles
drivers: arcv2_timer0: rename overflow_cyc to overflow_cycles

* rename overflow_cyc to overflow_cycles for better understanding
* use MIN macro to replace if .. else ..
* typo fix in comments

Signed-off-by: Wayne Ren <d5c6d7c4aa45e53f819f17870783d153a32ba7d0@synopsys.com>

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