drm/xe: Add new SVM copy GT stats per size

drm/xe: Add new SVM copy GT stats per size

Breakdown the GT stats for copy to host and copy to device per size (4K,
64K 2M) to make it easier for user space to track memory migrations.
This is helpful to verify allocation alignment is correct when porting
applications to SVM.

Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260325160152.1057556-1-francois.dugast@intel.com