drm/xe/gt: tweak placement for signalling TLB fences after GT reset

drm/xe/gt: tweak placement for signalling TLB fences after GT reset

Assumption here is that submission is disabled along with CT, and full
GT reset will also nuke TLBs, so should be safe to signal all in-flight
TLB fences, but only after the actual reset so move the placement
slightly.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>