drm/xe: Move page fault init after topology init

We need the topology to determine GT page fault queue size, move page
fault init after topology init.

Cc: stable@vger.kernel.org
Fixes: 3338e4f9 ("drm/xe: Use topology to determine page fault queue size")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Link: https://lore.kernel.org/r/20250710191208.1040215-1-matthew.brost@intel.com