reproduce (this is a W=1 build):
        # https://github.com/jpirko/linux_mlxsw/commit/1fbb59be0a8c4b5d5f56b10f397f6b085018733e
        git remote add jpirko-mlxsw https://github.com/jpirko/linux_mlxsw
        git fetch --no-tags jpirko-mlxsw wip_attestation_pre_rfc_draft1
        git checkout 1fbb59be0a8c4b5d5f56b10f397f6b085018733e

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash drivers/attestation/