[clang] [llvm] [lld] [AMDGPU] Rename COV module flag to amdhsa_code_object_version (PR #79905)

[Emma Pilkington via llvm-commits]

epilk wrote:

@tstellar there was some uncertainty about whether to leave the spelling as-is since mesa used to following HSA code object versions (but doesn't anymore). Would you have any objections to this change?

https://github.com/llvm/llvm-project/pull/79905