reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://github.com/morimoto/linux/commit/4cdb5f565ea7ee01981561ad699b3598c045418e
        git remote add morimoto https://github.com/morimoto/linux
        git fetch --no-tags morimoto gen5-VDK-3.1-2024-04-15
        git checkout 4cdb5f565ea7ee01981561ad699b3598c045418e
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/net/can/rcar/