drm/i915: Program iboost settings for HDMI/DVI on SKL

drm/i915: Program iboost settings for HDMI/DVI on SKL

commit 7ff9a55614712adf13ce7990565be0263e620f5e upstream.

Currently we fail to program the iboost stuff for HDMI/DVI. Let's remedy
that.

Fixes: f8896f5d58e6 ("drm/i915/skl: Buffer translation improvements")
Cc: David Weinehall <david.weinehall@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1468328376-6380-4-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
(cherry picked from commit 8d8bb85eb7d859aa9bbe36e588690a1d22af7608)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>