Add HSTU kernel repo (#2452)
Summary:
Enable HSTU kernels in the OSS.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/2452
Test Plan:
```
python run_benchmark.py triton --op addmm
```
Reviewed By: sijiac
Differential Revision: D62501334
Pulled By: xuzhao9
fbshipit-source-id: ce8258352f6fbbb9025c75942900144b2db581a9
