drm/tegra: dp - Mark the connector as hotplug capable

Doing so allows the hotplug events generated by the connector to be
properly handled by the DRM poll helpers.
Signed-off-by: NThierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/dpaux.c

@@ -414,6 +414,7 @@ int tegra_dpaux_attach(struct tegra_dpaux *dpaux, struct tegra_output *output)
 	unsigned long timeout;
 	int err;
 
+	output->connector.polled = DRM_CONNECTOR_POLL_HPD;
 	dpaux->output = output;
 
 	err = regulator_enable(dpaux->vdd);