No one looks at it, only i915/gma500 lvds even bother to fill it
out. I guess a very old plan was to use this for filtering modes,
but that's already done within the edid parser.

v2: Move misplaced hunk to this patch.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1471034937-651-18-git-send-email-daniel.vetter@ffwll.ch