drm/i915/bdw: check DPD on port D when setting the DDI buffers

Use the eDP values on platforms where port D is eDP. This doesn't
affect Haswell since it uses the same DDI buffer values for eDP and
DP.
Reviewed-by: Art Runyan <arthur.j.runyan@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_ddi.c

@@ -170,7 +170,12 @@ static void intel_prepare_ddi_buffers(struct drm_device *dev, enum port port)
 		break;
 	case PORT_B:
 	case PORT_C:
+		ddi_translations = ddi_translations_dp;
+		break;
 	case PORT_D:
+		if (intel_dpd_is_edp(dev))
+			ddi_translations = ddi_translations_edp;
+		else
 			ddi_translations = ddi_translations_dp;
 		break;
 	case PORT_E: