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/pci/pci.git/commit/?id=d4627402bd04795b039cb652bf0c6792ad654a84
        git remote add pci https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git
        git fetch --no-tags pci controller/imx6
        git checkout d4627402bd04795b039cb652bf0c6792ad654a84
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm64 olddefconfig
        ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash dtbs_check