Revert "drm/i915: Don't use the HDMI port color range bit on Valleyview"

Revert "drm/i915: Don't use the HDMI port color range bit on Valleyview"

The PIPECONF color range bit doesn't appear to be effective, on HDMI
outputs at least. The color range bit in the port register works though,
so let's use it.

I have not yet verified whether the PIPECONF bit works on DP outputs.

This reverts commit 6a2bcd2b2b9846c55e06e45e44dfc4ccbd46f8f7.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>