Revert "Support -fuse-ld=lld for riscv"
This reverts commit dd230142d8a00f5f30c3930a2407000e845dcfbf.
Failures:
http://lab.llvm.org:8011/builders/llvm-clang-win-x-armv7l/builds/4749
http://lab.llvm.org:8011/builders/llvm-clang-win-x-aarch64/builds/4752