drm/todo: Update mmap todo

Thanks to Noralf some good progress already.
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190614203615.12639-58-daniel.vetter@ffwll.ch

Documentation/gpu/todo.rst

@@ -162,7 +162,7 @@ Clean up mmap forwarding
 
 A lot of drivers forward gem mmap calls to dma-buf mmap for imported buffers.
 And also a lot of them forward dma-buf mmap to the gem mmap implementations.
-Would be great to refactor this all into a set of small common helpers.
+There's drm_gem_prime_mmap() for this now, but still needs to be rolled out.
 
 Contact: Daniel Vetter