drm/i915: Move bxt_ddi_vswing_sequence() call into intel_ddi_pre_enable() for HDMI

Now that the SKL iboost programming is done from intel_ddi_pre_enable()
for HDMI, let's move the BXT bxt_ddi_vswing_sequence() call there as
well. This makes things look more similar to the DP/eDP case which
is handled in ddi_signal_levels().

Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1468328376-6380-5-git-send-email-ville.syrjala@linux.intel.comReviewed-by: Imre Deak <imre.deak@intel.com>

drivers/gpu/drm/i915/intel_ddi.c

@@ -301,9 +301,6 @@ static const struct bxt_ddi_buf_trans bxt_ddi_translations_hdmi[] = {
 	{ 154, 0x9A, 1, 128, true },	/* 9:	1200		0   */
 };
 
-static void bxt_ddi_vswing_sequence(struct drm_i915_private *dev_priv,
-				    u32 level, enum port port, int type);
-
 static void ddi_get_encoder_port(struct intel_encoder *intel_encoder,
 				 struct intel_digital_port **dig_port,
 				 enum port *port)
@@ -446,15 +443,8 @@ void intel_prepare_ddi_buffer(struct intel_encoder *encoder)
 	port = intel_ddi_get_encoder_port(encoder);
 	hdmi_level = intel_ddi_hdmi_level(dev_priv, port);
 
-	if (IS_BROXTON(dev_priv)) {
-		if (encoder->type != INTEL_OUTPUT_HDMI)
-			return;
-
-		/* Vswing programming for HDMI */
-		bxt_ddi_vswing_sequence(dev_priv, hdmi_level, port,
-					INTEL_OUTPUT_HDMI);
+	if (IS_BROXTON(dev_priv))
 		return;
-	}
 
 	if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv)) {
 		ddi_translations_fdi = NULL;
@@ -1676,6 +1666,9 @@ static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
 
 		if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv))
 			skl_ddi_set_iboost(intel_encoder, level);
+		else if (IS_BROXTON(dev_priv))
+			bxt_ddi_vswing_sequence(dev_priv, level, port,
+						INTEL_OUTPUT_HDMI);
 
 		intel_hdmi->set_infoframes(encoder,
 					   crtc->config->has_hdmi_sink,