Add doxygen comments for PAPI_event_code_to_name() and PAPI_event_name_to_code()
Add doxygen comments for PAPI_event_code_to_name() and PAPI_event_name_to_code()

arm-hpc/papi,pyrovski/papi,pyrovski/papi,pyrovski/papi,arm-hpc/papi,arm-hpc/papi,pyrovski/papi,pyrovski/papi,arm-hpc/papi,pyrovski/papi,arm-hpc/papi,arm-hpc/papi,arm-hpc/papi,pyrovski/papi,pyrovski/papi