[clang] [NFC][Driver][HIP] Fix mixing `amdgcnspirv` and `gfxXXX` via `--offload-arch` (PR #133024)

[Joseph Huber via cfe-commits]

https://github.com/jhuber6 approved this pull request.

Seems in line with the weird workarounds we already use.

https://github.com/llvm/llvm-project/pull/133024