reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install powerpc cross compiling tool for clang build
        # apt-get install binutils-powerpc-linux-gnu
        # https://github.com/thesofproject/linux/commit/959fde874df9675d3cf934569ac9c0ea36cec285
        git remote add thesofproject https://github.com/thesofproject/linux
        git fetch --no-tags thesofproject topic/sof-dev-rebase
        git checkout 959fde874df9675d3cf934569ac9c0ea36cec285
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-15 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-15 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash sound/firewire/