There is only one queue for now, so for non-shared semaphores, the
implementation is basically a no-op. For shared semaphores, this
always uses syncobjs. This depends on syncobj support in the msm
kernel driver.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2769>
This diverged back in f1374805a8 ("drm-uapi: use local files, not system
libdrm") to point at drm-uapi's copy, which we don't need now that we're
actually in drm-uapi.
Reviewed-by: Rob Clark <robdclark@gmail.com>
