Merge remote-tracking branch 'airlied/drm-prime-vmap' into drm-intel-next-queued

We need the latest dma-buf code from Dave Airlie so that we can pimp
the backing storage handling code in drm/i915 with Chris Wilson's
unbound tracking and stolen mem backed gem object code.

Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>