cpufreq: Clean up header files included in the core

This patch addresses the following issues in the header files in the
cpufreq core:
 - Include headers in ascending order, so that we don't add same
   many times by mistake.
 - <asm/> must be included after <linux/>, so that they override
   whatever they need to.
 - Remove unnecessary includes.
 - Don't include files already included by cpufreq.h or
   cpufreq_governor.h.

[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/cpufreq.c

@@ -17,24 +17,17 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
-#include <asm/cputime.h>
-#include <linux/kernel.h>
-#include <linux/kernel_stat.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/notifier.h>
+#include <linux/cpu.h>
 #include <linux/cpufreq.h>
 #include <linux/delay.h>
-#include <linux/interrupt.h>
-#include <linux/spinlock.h>
-#include <linux/tick.h>
 #include <linux/device.h>
-#include <linux/slab.h>
-#include <linux/cpu.h>
-#include <linux/completion.h>
+#include <linux/init.h>
+#include <linux/kernel_stat.h>
+#include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/slab.h>
 #include <linux/syscore_ops.h>
-
+#include <linux/tick.h>
 #include <trace/events/power.h>
 
 /**