pvr: Submit PR commands

pvr: Submit PR commands

This commit adds a partial render command to job submission.
For geom only jobs we must always submit a pr command in case we
enter SPM. For now, for geom+frag jobs, we'll also always submit
a pr command event.

Signed-off-by: Karmjit Mahil <Karmjit.Mahil@imgtec.com>
Reviewed-by: Frank Binns <frank.binns@imgtec.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24138>