drm/xe: Use GT oriented log messages in xe_gt.c

Replace generic log messages with ones dedicated for the GT.
While around replace errno logs from plain %d to pretty %pe.

v2: rebased
v3: unify errno logs

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>