drm/atmel-hlcdc: Use simple encoder

The atmel-hlcdc driver uses an empty implementation for its encoder.
Replace the code with the generic simple encoder.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200305155950.2705-3-tzimmermann@suse.de

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c

@@ -11,9 +11,10 @@
 #include <linux/media-bus-format.h>
 #include <linux/of_graph.h>
 
+#include <drm/drm_bridge.h>
 #include <drm/drm_encoder.h>
 #include <drm/drm_of.h>
-#include <drm/drm_bridge.h>
+#include <drm/drm_simple_kms_helper.h>
 
 #include "atmel_hlcdc_dc.h"
 
@@ -22,10 +23,6 @@ struct atmel_hlcdc_rgb_output {
 	int bus_fmt;
 };
 
-static const struct drm_encoder_funcs atmel_hlcdc_panel_encoder_funcs = {
-	.destroy = drm_encoder_cleanup,
-};
-
 static struct atmel_hlcdc_rgb_output *
 atmel_hlcdc_encoder_to_rgb_output(struct drm_encoder *encoder)
 {
@@ -98,9 +95,8 @@ static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint)
 		return -EINVAL;
 	}
 
-	ret = drm_encoder_init(dev, &output->encoder,
-			       &atmel_hlcdc_panel_encoder_funcs,
-			       DRM_MODE_ENCODER_NONE, NULL);
+	ret = drm_simple_encoder_init(dev, &output->encoder,
+				      DRM_MODE_ENCODER_NONE);
 	if (ret)
 		return ret;