reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux.git/commit/?id=720fd1cbc0a0f3acdb26aedb3092ab10fe05e7ae
        git remote add shawnguo https://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux.git
        git fetch --no-tags shawnguo imx/fixes
        git checkout 720fd1cbc0a0f3acdb26aedb3092ab10fe05e7ae
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash dtbs_check