drm/xe: Remove unused GT page fault code

With the Xe page fault layer and GuC page layer in place, this is now
dead code and can be removed. ACC code is also removed, but this was
dead code.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Tested-by: Francois Dugast <francois.dugast@intel.com>
Link: https://patch.msgid.link/20251031165416.2871503-8-matthew.brost@intel.com

Author: mbrost05