Fix the lld link error on ppc64le builders:
ld.lld: error: undefined symbol: llvm::createLoopDataPrefetchPass() >>> referenced by LoongArchTargetMachine.cpp >>> lib/Target/LoongArch/CMakeFiles/LLVMLoongArchCodeGen.dir/LoongArchTargetMachine.cpp.o:((anonymous namespace)::LoongArchPassConfig::addIRPasses()) collect2: error: ld returned 1 exit status`