[clang] [clang][Driver][OpenMP][SPIR-V] Fix SPIR-V OpenMP DeviceRTL expected file name (PR #141855)

[Joseph Huber via cfe-commits]

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

The `.bc` file for AMDGPU is unused, I'd imagine SPIR-V is as well since its compilation flow is like AMDGPU.

https://github.com/llvm/llvm-project/pull/141855