drm/msm: for array in-fences, check if all backing fences are from our own context...

drm/msm: for array in-fences, check if all backing fences are from our own context before waiting

Use the dma_fence_match_context helper to check if all backing fences
are from our own context, in which case we don't have to wait.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Gustavo Padovan <gustavo.padovan@collabora.com>
[rebased on code-motion]
Signed-off-by: Rob Clark <robdclark@gmail.com>