drm/sched: Embed run queue singleton into the scheduler

drm/sched: Embed run queue singleton into the scheduler

Now that the run queue to scheduler relationship is always 1:1 we can
embed it (the run queue) directly in the scheduler struct and save on
some allocation error handling code and such.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Philipp Stanner <phasta@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Tested-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patch.msgid.link/20260417103744.76020-15-tvrtko.ursulin@igalia.com