FYI, for anyone else looking, you can find the L4T release via “head -n 1 /etc/nv_tegra_release”. You can then find the documentation for your specific release here:
https://developer.nvidia.com/linux-tegra
Once there, the documentation will tell you about cross compile and tools. There is usually (always? often? don’t know) an actual copy of the compiler in the tools link.