drm/i915: Add some debug breadcrumbs to connector detection

Try to decypher detection failures is a little tricker at the moment as
the only indicator of progress is when output_poll_execute() tells us
the result after the connector->detect() has run. This patch adds a
telltale to the start of each detect function so that we can track
progress and associate activity more clearly with each connector.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_lvds.c

@@ -339,6 +339,9 @@ intel_lvds_detect(struct drm_connector *connector, bool force)
 	struct drm_device *dev = connector->dev;
 	enum drm_connector_status status;
 
+	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
+		      connector->base.id, drm_get_connector_name(connector));
+
 	status = intel_panel_detect(dev);
 	if (status != connector_status_unknown)
 		return status;