udmabuf: Add missing compact_ioctl

Make sure we can use this on mixed systems.

Signed-off-by: Kristian H. Kristensen <hoegsberg@google.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200903181652.432067-1-hoegsberg@google.com


Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>