reproduce (this is a W=1 build):
        # https://github.com/jpirko/linux_mlxsw/commit/611edc69440d968bf06f3c4018b4a3b4a4660884
        git remote add jpirko-mlxsw https://github.com/jpirko/linux_mlxsw
        git fetch --no-tags jpirko-mlxsw wip_attestation_all_1
        git checkout 611edc69440d968bf06f3c4018b4a3b4a4660884

        # install powerpc64 cross compiling tool for clang build
        # apt-get install binutils-powerpc64-linux-gnu
        # clang-24 might not be officially released. Try a lower version if installation fails.
        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=$HOME/0day COMPILER=clang-24 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-24 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash drivers/ctlv/