Even though the documentation suggests that there are 3 RTCs (RTC0, RTC1 and RTC2) and the file nrf52.h has a declaration for the RTC2 peripleral, I am not able to use it. The file nRF52_SDK_0.9.2_dbc28c9\components\drivers_nrf\config\nrf_drv_config.h has no reference to RTC2.