Retrieves a performance mode string with all the performance modes defined for this device along with their associated GPU Clock and Memory Clock values. Not all tokens will be reported on all GPUs, and additional tokens may be added in the future. For backwards compatibility we still provide nvclock and memclock; those are the same as nvclockmin and memclockmin.
:param device: The identifier of the target device.
:type device: intptr_t
:returns: The performance level string.
:rtype: str
.. seealso:: `nvmlDeviceGetPerformanceModes`
