drm/xe/reg_sr: Use xe_gt_dbg

Use xe_gt_dbg() instead of drm_dbg() so the GT is added to the log for
easy identification.

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://lore.kernel.org/r/20230906012053.1733755-3-lucas.demarchi@intel.com


Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>