Add a number of require includes and forward declare struct
drm_crtc. s/crc/crcs/ kernel-doc to match code.
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/290b006bb348a03bd7c4c062d337df21fdaced53.1709749576.git.jani.nikula@intel.com