reproduce (this is a W=1 build):
        # https://github.com/Xilinx/linux-xlnx/commit/f2009da08ef7c8990f5b89780b3d21335f00ed1a
        git remote add xilinx-xlnx https://github.com/Xilinx/linux-xlnx
        git fetch --no-tags xilinx-xlnx xlnx_rebase_v6.18_LTS
        git checkout f2009da08ef7c8990f5b89780b3d21335f00ed1a

        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        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=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/phy/xilinx/ drivers/staging/xlnx-mmi-dptx/