sched/rt: Fix Sparse warnings due to undefined rt.c declarations

There are several symbols defined in kernel/sched/sched.h but get wrapped
in CONFIG_CGROUP_SCHED, even though dummy versions get built in rt.c and
therefore trigger Sparse warnings:

  kernel/sched/rt.c:309:6: warning: symbol 'unregister_rt_sched_group' was not declared. Should it be static?
  kernel/sched/rt.c:311:6: warning: symbol 'free_rt_sched_group' was not declared. Should it be static?
  kernel/sched/rt.c:313:5: warning: symbol 'alloc_rt_sched_group' was not declared. Should it be static?

Fix this by moving them outside the CONFIG_CGROUP_SCHED block.

[ mingo: Refreshed to the latest scheduler tree, tweaked changelog. ]

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20220721145155.358366-1-ben-linux@fluff.org

kernel/sched/sched.h

@@ -480,9 +480,6 @@ extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
 
-extern void unregister_rt_sched_group(struct task_group *tg);
-extern void free_rt_sched_group(struct task_group *tg);
-extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
 		struct sched_rt_entity *rt_se, int cpu,
 		struct sched_rt_entity *parent);
@@ -520,6 +517,10 @@ struct cfs_bandwidth { };
 
 #endif	/* CONFIG_CGROUP_SCHED */
 
+extern void unregister_rt_sched_group(struct task_group *tg);
+extern void free_rt_sched_group(struct task_group *tg);
+extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
+
 /*
  * u64_u32_load/u64_u32_store
  *