[clang] [AMDGPU][SPIR-V] Fix treating SPIR-V input as the wrong LLVM-IR (PR #202986)

[Dmitry Sidorov via cfe-commits]

MrSidims wrote:

> : CommandLine Error: Option 'spirv-preserve-auxdata' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options

AFAIK that should have been fixed already. FYI @aobolensk 

https://github.com/llvm/llvm-project/pull/202986