reproduce:
        git remote add pengutronix https://git.pengutronix.de/git/linux-0-day
        git fetch --no-tags pengutronix mfe/v6.19/topic/touchscreen-axiom
        git checkout a2c0b8aee58d5ef254750920bb8a89e4caaadbab
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs