First the internal `include` and `os` directories:
```
cp -r /playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/include/nvgpu/
cp -r /playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/os include/
```

Then every directory needed by either of those includes:
```
cp -r /playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/os include/
/playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/gk20a include/
/playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/ctrl include/
/playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/clk include/
/playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/boardobj include/
/playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/pmu_perf include/
/playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/pstate include/
/playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/volt include/
/playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/lpwr include/
/playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/pmgr include/
/playpen/Linux_for_Tegra/source/public/kernel/nvgpu/drivers/gpu/nvgpu/therm include/
```

Make sure to pull the same version of L4T that you're building on! The structure layout is highly dependant on the version.