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/soc/soc.git/commit/?id=5147708ee812a5eac5202f231d48b5be1fea781d
        git remote add soc https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git
        git fetch --no-tags soc renesas/dt64-4
        git checkout 5147708ee812a5eac5202f231d48b5be1fea781d
        # 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