[llvm] [CodeGen][Mips] Explicit ELF output file format for MIPS tests (PR #114678)

[YunQiang Su via llvm-commits]

wzssyqa wrote:

I don't think that we should have these test case modification.
I mean that ELF should be kept as the default value for MIPS.

https://github.com/llvm/llvm-project/pull/114678