reproduce (this is a W=1 build):
        # https://github.com/masneyb/linux/commit/35ae2ca226ff0b0f5ca4e9f3ce658d1ba7874e91
        git remote add masneyb https://github.com/masneyb/linux
        git fetch --no-tags masneyb b4/clk-scaling
        git checkout 35ae2ca226ff0b0f5ca4e9f3ce658d1ba7874e91

        # install um cross compiling tool for clang build
        # apt-get install binutils-um-linux-gnu
        # clang-23 might not be officially released. Try a lower version if installation fails.
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-23 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=um olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-23 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=um SHELL=/bin/bash drivers/clk/