drm/i915: s/INTEL_OUTPUT_DISPLAYPORT/INTEL_OUTPUT_DP/

INTEL_OUTPUT_DISPLAYPORT hsa been bugging me for a long time. It always
looks out of place besides INTEL_OUTPUT_EDP and INTEL_OUTPUT_DP_MST.
Let's just rename it to INTEL_OUTPUT_DP.

v2: Rebase

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466621833-5054-9-git-send-email-ville.syrjala@linux.intel.com
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 9da4bef..9079455 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4040,7 +4040,7 @@
 	struct intel_encoder *encoder;
 
 	for_each_encoder_on_crtc(dev, crtc, encoder) {
-		if (encoder->type == INTEL_OUTPUT_DISPLAYPORT ||
+		if (encoder->type == INTEL_OUTPUT_DP ||
 		    encoder->type == INTEL_OUTPUT_EDP)
 			return enc_to_dig_port(&encoder->base)->port;
 	}
@@ -5128,7 +5128,7 @@
 	case INTEL_OUTPUT_UNKNOWN:
 		/* Only DDI platforms should ever use this output type */
 		WARN_ON_ONCE(!HAS_DDI(dev));
-	case INTEL_OUTPUT_DISPLAYPORT:
+	case INTEL_OUTPUT_DP:
 	case INTEL_OUTPUT_HDMI:
 	case INTEL_OUTPUT_EDP:
 		intel_dig_port = enc_to_dig_port(&intel_encoder->base);
@@ -5162,7 +5162,7 @@
 		 * run the DP detection too.
 		 */
 		WARN_ON_ONCE(!HAS_DDI(dev));
-	case INTEL_OUTPUT_DISPLAYPORT:
+	case INTEL_OUTPUT_DP:
 	case INTEL_OUTPUT_EDP:
 		intel_dig_port = enc_to_dig_port(&intel_encoder->base);
 		return port_to_aux_power_domain(intel_dig_port->port);
@@ -12377,7 +12377,7 @@
 		case INTEL_OUTPUT_UNKNOWN:
 			if (WARN_ON(!HAS_DDI(dev)))
 				break;
-		case INTEL_OUTPUT_DISPLAYPORT:
+		case INTEL_OUTPUT_DP:
 		case INTEL_OUTPUT_HDMI:
 		case INTEL_OUTPUT_EDP:
 			port_mask = 1 << enc_to_dig_port(&encoder->base)->port;