[Feature][AMD] Adding fp8 Gemm Computation

[charlifu]

This PR adds fp8 gemm computation support on AMD GPUs.

• Moved convert_fp8 kernels to vllm.ops from vllm.cache_ops.
• Added Fp8RocmConfig and Fp8RocmLinearMethod for creating fp8 weights and conducting fp8 gemm computation.
• Added pytorch C++ ops warping hipblaslt kernels for fp8 gemm.

[mawong-amd]

Thanks for your hard work on this! I've given the PR a very quick look and given a few comments mostly relating to style/structure. Will do a more in-depth read once it's a bit more mature.

[mawong-amd]

Nit: better description explaining the difference between these two.

[charlifu]

Sure, will do.

[HaiShaw]

More changes needed:
7. code style and line formats - vLLM required google style, it will trigger many errors as current standing, e.g. keep line break at 80 max, etc. Using our prior merged code as an example to be safe.
8. fp8_gemm - please consider to add bias support.

[HaiShaw]

Do we have Dockerfile updated to reflect the changes needed for libraries - hipblas, etc.?
Providing a reference public docker image (on MI300x) can be an alternative, but we need to describe it in writeup.

[gshtras]

Do we have Dockerfile updated to reflect the changes needed for libraries - hipblas, etc.? Providing a reference public docker image (on MI300x) can be an alternative, but we need to describe it in writeup.

Dockerfile.rocm in our fork has all that's needed. Dockerfile.rocm in upstream should also work, but I doubt it was tested for fp8

[HaiShaw]

Please rename csrc/quantization/fp8/amd/gemm_kernel.cu, it isn't a cuda kernel file, using .cu isn't appropriate.

[gshtras]

Please rename csrc/quantization/fp8/amd/gemm_kernel.cu, it isn't a cuda kernel file, using .cu isn't appropriate.

It uses the generic cublas API, and therefore:

1. Is CUDA compatible
2. Needs to be hippified
3. Needs to have this extension for CMake to work correctly, and apply hipifier

[HaiShaw]

LGTM for now, we can address remaining open issues continuously.

Once merged to fp8-gemm, we can put obvious and build fixes, etc. on fp8-gemm directly, a bit more involved can use this or other branches too targeting fp8-gemm, until upcoming UPSTREAM from fp8-gemm is finally merged.