Update lit.local.cfg

Author: makslevental

mlir/test/Examples/standalone/lit.local.cfg

@@ -14,3 +14,4 @@ config.substitutions.append(("%cmake_build_type", config.cmake_build_type))
 config.substitutions.append(("%llvm_obj_root", config.llvm_obj_root))
 config.substitutions.append(("%llvm_src_root", config.llvm_src_root))
 config.substitutions.append(("%host_cmake_install_prefix", config.host_cmake_install_prefix))
+config.substitutions.append(("%host_cmake_cmd", config.host_cmake))