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: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
index 208fc1b..3f132e3 100644
--- a/drivers/gpu/drm/tegra/dpaux.c
+++ b/drivers/gpu/drm/tegra/dpaux.c
@@ -414,6 +414,7 @@
 	unsigned long timeout;
 	int err;
 
+	output->connector.polled = DRM_CONNECTOR_POLL_HPD;
 	dpaux->output = output;
 
 	err = regulator_enable(dpaux->vdd);