drm/renesas/rcar-du: Use fbdev-dma

Implement fbdev emulation with fbdev-dma. Fbdev-dma now supports
damage handling, which is required by rcar-du. Avoids the overhead of
fbdev-generic's additional shadow buffering. No functional changes.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240419083331.7761-29-tzimmermann@suse.de

drivers/gpu/drm/renesas/rcar-du/rcar_du_drv.c

@@ -20,7 +20,7 @@
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_drv.h>
-#include <drm/drm_fbdev_generic.h>
+#include <drm/drm_fbdev_dma.h>
 #include <drm/drm_gem_dma_helper.h>
 #include <drm/drm_managed.h>
 #include <drm/drm_probe_helper.h>
@@ -716,7 +716,7 @@ static int rcar_du_probe(struct platform_device *pdev)
 
 	drm_info(&rcdu->ddev, "Device %s probed\n", dev_name(&pdev->dev));
 
-	drm_fbdev_generic_setup(&rcdu->ddev, 32);
+	drm_fbdev_dma_setup(&rcdu->ddev, 32);
 
 	return 0;