drivers: counter: nrf_rtc: Fix wrapping with PPI
drivers: counter: nrf_rtc: Fix wrapping with PPI

PPI allocation and freeing was not handled correctly. Additionally,
RTC event was not enabled when PPI was enabled which resulted in
lack of RTC counter clearing.

Signed-off-by: Krzysztof Chruscinski <9b6dc988558c51b0405b49b55c8e66862969844b@nordicsemi.no>

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