drm/i915: Drop the eDP paths from the pre-Ironlake crtc_mode_set.

While g4x had DP, eDP came with Ironlake, so we don't need that code here.

Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>