drm/msm: Add syncobj support.

This

1) Enables core DRM syncobj support.
2) Adds options to the submission ioctl to wait/signal syncobjs.

Just like the wait fence fd, this does inline waits. Using the
scheduler would be nice but I believe it is out of scope for
this work.

Support for timeline syncobjs is implemented and the interface
is ready for it, but I'm not enabling it yet until there is
some code for turnip to use it.

The reset is mostly in there because in the presence of waiting
and signalling the same semaphores, resetting them after
signalling can become very annoying.

v2:
  - Fixed style issues
  - Removed a cleanup issue in a failure case
  - Moved to a copy_from_user per syncobj

v3:
 - Fixed a missing declaration introduced in v2
 - Reworked to use ERR_PTR/PTR_ERR
 - Simplified failure gotos.

Used by: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2769



Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>