reproduce:
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # apt-get install sparse
        # sparse version: v0.6.4-47-g365b9520-dirty
        # https://github.com/intel-lab-lkp/linux/commit/f9e309400d44865c2c7e1728842bb0b4ff566a38
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Tobias-Waldekranz/net-dsa-mv88e6xxx-Add-LED-infrastructure/20240103-183726
        git checkout f9e309400d44865c2c7e1728842bb0b4ff566a38
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=loongarch olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=loongarch SHELL=/bin/bash drivers/net/dsa/mv88e6xxx/