drm/mcde: Use GEM DMA fbdev emulation

Use the fbdev emulation that is optimized for DMA helpers. Avoids
possible shadow buffering and makes the code simpler.
Reported-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/dri-devel/CACRpkdawSQsNqKJkSSoSw3HmMHyNXFUywxkdszpTC-a_uZA+tQ@mail.gmail.com/Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230313155138.20584-25-tzimmermann@suse.de

drivers/gpu/drm/mcde/mcde_drv.c

@@ -69,7 +69,7 @@
 #include <drm/drm_bridge.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_fb_dma_helper.h>
-#include <drm/drm_fbdev_generic.h>
+#include <drm/drm_fbdev_dma.h>
 #include <drm/drm_gem.h>
 #include <drm/drm_gem_dma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
@@ -237,7 +237,7 @@ static int mcde_drm_bind(struct device *dev)
 	if (ret < 0)
 		goto unbind;
 
-	drm_fbdev_generic_setup(drm, 32);
+	drm_fbdev_dma_setup(drm, 32);
 
 	return 0;