drm/v3d: Add more tracepoints for V3D GPU rendering.

The core scheduler tells us when the job is pushed to the scheduler's
queue, and I had the job_run functions saying when they actually queue
the job to the hardware.  By adding tracepoints for the very top of
the ioctls and the IRQs signaling job completion, "perf record -a -e
v3d:.\* -e gpu_scheduler:.\* <job>; perf script" gets you a pretty
decent timeline.

Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20181201005759.28093-5-eric@anholt.net


Reviewed-by: Dave Emett <david.emett@broadcom.com>