drm/xe/gt: Drop third submission for default context

drm/xe/gt: Drop third submission for default context

There's no need to submit the nop job again on the first queue. Any
state needed is already saved when the first LRC is switched out. The
comment is a little misleading regarding indirect W/A: first of all
there's still no indirect W/A enabled and secondly, even after they are,
there's no need to submit this job again for having their state
propagated: the indirect W/A will actually run on every LRC switch.

Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250710-lrc-refactors-v2-6-a5e2ca03f6bd@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>