Drop extraneaous llvm::cl::MiscFlags::CommaSeparated from Passes.td
Drop extraneaous llvm::cl::MiscFlags::CommaSeparated from Passes.td

These become compilation errors in the next LLVM bump.

iree-org/iree-llvm-sandbox,iree-org/iree-llvm-sandbox,iree-org/iree-llvm-sandbox,iree-org/iree-llvm-sandbox