drm/i915: Use connector->name in drrs debugfs.

This removes relying on intel_encoder->type, which may be set to
unknown.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466431059-8919-2-git-send-email-maarten.lankhorst@linux.intel.com


Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>