sched/headers: Remove the <linux/topology.h> include from <linux/sched.h>

It's used only by a single (rarely used) inline function (task_node(p)),
which we can move to <linux/sched/topology.h>.

( Add <linux/nodemask.h>, because we rely on that. )

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/sched/topology.h

@@ -1,6 +1,8 @@
 #ifndef _LINUX_SCHED_TOPOLOGY_H
 #define _LINUX_SCHED_TOPOLOGY_H
 
+#include <linux/topology.h>
+
 #include <linux/sched/idle.h>
 
 /*
@@ -216,4 +218,9 @@ static inline bool cpus_share_cache(int this_cpu, int that_cpu)
 
 #endif	/* !CONFIG_SMP */
 
+static inline int task_node(const struct task_struct *p)
+{
+	return cpu_to_node(task_cpu(p));
+}
+
 #endif /* _LINUX_SCHED_TOPOLOGY_H */