linux-phytec-ti

drm/doc: Document drm_add_modes_noedid() usage

And fix a spelling mistake.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>