Hi usajpn,
Please refer to USB Lane Mapping in
Tegra_Linux_Driver_Package_Documents_R24.2 → Start_L4T_Docs.html → Downloads → Platform Adaptation and Bring-Up Guide (PDF)
https://developer.nvidia.com/embedded/dlc/l4t-documentation-24-2-1
Another example for reference https://devtalk.nvidia.com/default/topic/987809/?comment=5056353