[llvm] [runtimes] Fix duplicate BUILTINS_CMAKE_ARGS/RUNTIMES_CMAKE_ARGS (PR #160631)

[via llvm-commits]

thetruestblue wrote:

without digging too much into this my only question is no canon name != BUILTIN needs the BUILTIN args? if true then yes this makes sense.

https://github.com/llvm/llvm-project/pull/160631