[llvm] [AMDGPU] Fix layering violations in AMDGPUMCExpr.cpp. NFC (PR #168242)

[Sergei Barannikov via llvm-commits]

https://github.com/s-barannikov commented:

It doesn't fix all layering violations, right? AMDGPUDesc still depends on Core and AMDGPUUtils that depends on Core.


https://github.com/llvm/llvm-project/pull/168242