ANDROID: sched: add vendor data to root_domain

We add vendor data to root_domain to record
whether heavy tasks in system exceed a certain amount.
This support heavy tasks' load balance by two vendor hooks,
1. trace_android_vh_scheduler_tick
2. trace_android_rvh_sched_newidle_balance

Bug: 316475976
Bug: 377175548

Signed-off-by: Peter-TY Tsai <peter-ty.tsai@mediatek.com>
Change-Id: I21b68059153dc6e94bb86e3e54af04cb06ec5175

kernel/sched/sched.h

@@ -1025,6 +1025,8 @@ struct root_domain {
 	 * CPUs of the rd. Protected by RCU.
 	 */
 	struct perf_domain __rcu *pd;
+
+	ANDROID_VENDOR_DATA(1);
 };
 
 extern void init_defrootdomain(void);