drm/i915: Don't mark eDP encoders as MST capable

If we've determined that the encoder is eDP, we shouldn't try to use MST
on it. Or at least the code doesn't seem to expect that since there are
some type==DP checks in the MST code.

Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NShashank Sharma <shashank.sharma@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466621833-5054-2-git-send-email-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/intel_dp.c

@@ -5615,7 +5615,7 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
 	}
 
 	/* init MST on ports that can support it */
-	if (HAS_DP_MST(dev) &&
+	if (HAS_DP_MST(dev) && !is_edp(intel_dp) &&
 	    (port == PORT_B || port == PORT_C || port == PORT_D))
 		intel_dp_mst_encoder_init(intel_dig_port,
 					  intel_connector->base.base.id);