Seems gpu-burn only uses nvidia-smi for monitoring GPU temperature. You may find similar temperature information from tegrastats or from sysfs (PMIC temperature in tegrastats output - #4 by Honey_Patouceul), so you may adapt gpu-burn code and rebuild for Jetson.
Note that there may be other adaptations, for example memory management which is different because iGPU on Jetson shares the same physical memory than CPUs.