Blender Git Loki

Cycles X: Use queue for data transfer in naive GPU update

Run into this code while looking into the following issue:
when using non-display GPU and OpenImageDenoiser in viewport
sometimes during navigation the viewport goes blank.

This change seems to either fix this issue (although, not
entirely sure why, because from my understanding all the calls
were already properly synchronized).

In any case, using a queue for data transfers and kernel is
more correct way to go.

If the issue described above ever comes back we will dig
deeper.