hip_fp8.h doesn't exist before hip 6.2

[m-kim]

To maintain backwards compatibility with versions of HIP prior to 6.2.

[m-kim]

I understand this might not be the best way to fix it, specifically that I check for the existence of OCP. I'm open to suggestions.

[cmingch]

I understand this might not be the best way to fix it, specifically that I check for the existence of OCP. I'm open to suggestions.

i have similar PR https://github.com/ROCm/hipBLASLt/pull/1072/ before. due to i'm not sure if any one use hipblaslt with rocm less than 6.2, so PR has not been merged yet.

[jayhawk-commits]

Please resolve merge conflicts or close this PR to complete the task of importing PRs from this repo to the monorepo.