reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        # https://github.com/morimoto/linux/commit/ed34f19dbdc7a70ed09e863a509fb79f127694a3
        git remote add morimoto https://github.com/morimoto/linux
        git fetch --no-tags morimoto renesas-bsp/v6.1.112-2024-10-03-2
        git checkout ed34f19dbdc7a70ed09e863a509fb79f127694a3
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-15 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-15 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/net/phy/