drm/tegra: Remove remnants of the output midlayer

The tegra_output midlayer is now completely gone and output drivers use
it purely as a helper library.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/hdmi.c b/drivers/gpu/drm/tegra/hdmi.c
index b4fe909..03ceb50 100644
--- a/drivers/gpu/drm/tegra/hdmi.c
+++ b/drivers/gpu/drm/tegra/hdmi.c
@@ -1347,10 +1347,13 @@
 					  &hdmi->output.encoder);
 	drm_connector_register(&hdmi->output.connector);
 
-	hdmi->output.encoder.possible_crtcs = 0x3;
+	err = tegra_output_init(drm, &hdmi->output);
+	if (err < 0) {
+		dev_err(client->dev, "failed to initialize output: %d\n", err);
+		return err;
+	}
 
-	if (gpio_is_valid(hdmi->output.hpd_gpio))
-		enable_irq(hdmi->output.hpd_irq);
+	hdmi->output.encoder.possible_crtcs = 0x3;
 
 	if (IS_ENABLED(CONFIG_DEBUG_FS)) {
 		err = tegra_hdmi_debugfs_init(hdmi, drm->primary);