drm/virtio: Wait for each dma-fence of in-fence array individually

Use dma-fence-unwrap API for waiting each dma-fence of the in-fence array
individually. Sync file's in-fence array always has a non-matching fence
context ID, which doesn't allow to skip waiting of fences with a matching
context ID in a case of a merged sync file fence.

Suggested-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Tested-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230416115237.798604-3-dmitry.osipenko@collabora.com