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/clk/linux.git/commit/?id=9f7809c6a8824b7147595b3c36e633ffc81fe2ab
        git remote add clk https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git
        git fetch --no-tags clk clk-mediatek
        git checkout 9f7809c6a8824b7147595b3c36e633ffc81fe2ab
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm olddefconfig
        ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash dtbs_check