drm/crtc-helper: Remove most include statements from drm_crtc_helper.h

Remove most include statements from crm_crtc_helper.h and forward-
declare the contained types in drm_crtc_helper.h. Only keep <linux/types.h>
for the definition of 'bool'.

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230116131235.18917-23-tzimmermann@suse.de