nak: Add latency helpers to ShaderModel and use them

For now, these all just call into sched_common.rs but this gives us the
interface we really want going forward.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Mel Henning <mhenning@darkrefraction.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34302>
3 files changed