drm/xe: Remove drm_sched_init_args->num_rqs usage

drm/xe: Remove drm_sched_init_args->num_rqs usage

Remove member no longer used by the scheduler core.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-xe@lists.freedesktop.org
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patch.msgid.link/20260417103744.76020-29-tvrtko.ursulin@igalia.com