pps: allow drivers to report timestamps in their own time domain

pps: allow drivers to report timestamps in their own time domain

For this each driver must :

  - report its clock_id (if no particular clock just default to cpu
    boottime one)

  - be able to sample its clock (gpu_timestamp())

The PPSDataSource will then emit timestamp correlation events in the
trace ensuring perfetto is able to display GPU & CPU events
appropriately on its timeline.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Antonio Caggiano <antonio.caggiano@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13831>