drm/vc4: Use GEM DMA fbdev emulation

Use the fbdev emulation that is optimized for DMA helpers. Avoids
possible shadow buffering and makes the code simpler.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230313155138.20584-22-tzimmermann@suse.de

drivers/gpu/drm/vc4/vc4_drv.c

@@ -33,7 +33,7 @@
 #include <drm/drm_aperture.h>
 #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_vblank.h>
 
 #include <soc/bcm2835/raspberrypi-firmware.h>
@@ -387,7 +387,7 @@ static int vc4_drm_bind(struct device *dev)
 	if (ret < 0)
 		goto unbind_all;
 
-	drm_fbdev_generic_setup(drm, 16);
+	drm_fbdev_dma_setup(drm, 16);
 
 	return 0;