auxdisplay/cfag12864bfb: Set FBINFO_VIRTFB flag

The cfag12864bfb driver operates on system memory. Mark the framebuffer
accordingly. Helpers operating on the framebuffer memory will test for
the presence of this flag.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-8-tzimmermann@suse.de

drivers/auxdisplay/cfag12864bfb.c

@@ -72,6 +72,7 @@ static int cfag12864bfb_probe(struct platform_device *device)
 	if (!info)
 		goto none;
 
+	info->flags = FBINFO_VIRTFB;
 	info->screen_buffer = cfag12864b_buffer;
 	info->screen_size = CFAG12864B_SIZE;
 	info->fbops = &cfag12864bfb_ops;