udmabuf: use cache_sgt_mapping option
The GEM prime helpers do it, so should we. It's also possible to make it optional later. Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org> Link: http://patchwork.freedesktop.org/patch/msgid/20191203013627.85991-1-gurchetansingh@chromium.org Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>