drm/xe: Add xe_gt_tlb_invalidation_done_handler

Decouple GT TLB seqno handling from G2H handler.

v2:
 - Add kernel doc

Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250826182911.392550-6-stuart.summers@intel.com