sched/headers: Remove <linux/sched.h> from <linux/sched/cpufreq.h>

Make the <linux/sched/cpufreq.h> file a self-contained header and
remove the <linux/sched.h> dependency: users of it either don't
need <linux/sched.h> - or have already included it.

This reduces the size of the header dependency graph.
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/cpufreq.h

 #ifndef _LINUX_SCHED_CPUFREQ_H
 #define _LINUX_SCHED_CPUFREQ_H
 
-#include <linux/sched.h>
+#include <linux/types.h>
 
 /*
  * Interface between cpufreq drivers and the scheduler: