drm/i915/ehl: Enable DDI-D

EHL has four DDI's (DDI-A and DDI-D share combo PHY A).

Cc: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190709183934.445-6-matthew.d.roper@intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -15308,6 +15308,7 @@ static void intel_setup_outputs(struct drm_i915_private *dev_priv)
 		intel_ddi_init(dev_priv, PORT_A);
 		intel_ddi_init(dev_priv, PORT_B);
 		intel_ddi_init(dev_priv, PORT_C);
+		intel_ddi_init(dev_priv, PORT_D);
 		icl_dsi_init(dev_priv);
 	} else if (INTEL_GEN(dev_priv) >= 11) {
 		intel_ddi_init(dev_priv, PORT_A);