[llvm] AMDGPU/NFC: Reserve 0x056 and 0x057 EF_AMDGPU_MACHs (PR #92917)

[Shilei Tian via llvm-commits]

shiltian wrote:

I think you will also need changes in `llvm/lib/Object/ELFObjectFile.cpp`; otherwise the `default` will cause trap.

https://github.com/llvm/llvm-project/pull/92917