drm/xe: Save the gt pointer in lrc and drop the tile

Save the gt pointer in the lrc so that it can used for gt based helpers.

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250509161159.2173069-7-umesh.nerlige.ramappa@intel.com