ANDROID: sched: Calculate energy consumption of sched_group

For energy-aware load-balancing decisions it is necessary to know the
energy consumption estimates of groups of cpus. This patch introduces a
basic function, sched_group_energy(), which estimates the energy
consumption of the cpus in the group and any resources shared by the
members of the group.

NOTE: The function has five levels of identation and breaks the 80
character limit. Refactoring is necessary.

cc: Ingo Molnar <mingo@redhat.com>
cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Andres Oportus <andresoportus@google.com>
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 2e0f325..92d52b6 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -886,6 +886,7 @@
 DECLARE_PER_CPU(struct sched_domain *, sd_numa);
 DECLARE_PER_CPU(struct sched_domain *, sd_asym);
 DECLARE_PER_CPU(struct sched_domain *, sd_ea);
+DECLARE_PER_CPU(struct sched_domain *, sd_scs);
 
 struct sched_group_capacity {
 	atomic_t ref;