drm/omapdrm: Set fbdev FBINFO_VIRTFB flag

Mark the framebuffer with FBINFO_VIRTFB. The framebuffer range is
in DMA-able memory and should be accessed with the CPU's regular
memory ops.

v2:
	* drop FBINFO_DEFAULT

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230707083422.18691-11-tzimmermann@suse.de

Author: tdz

drivers/gpu/drm/omapdrm/omap_fbdev.c

@@ -207,6 +207,7 @@ static int omap_fbdev_create(struct drm_fb_helper *helper,
 
 	drm_fb_helper_fill_info(fbi, helper, sizes);
 
+	fbi->flags |= FBINFO_VIRTFB;
 	fbi->screen_buffer = omap_gem_vaddr(bo);
 	fbi->screen_size = bo->size;
 	fbi->fix.smem_start = dma_addr;