cpufreq: Use clamp() helper macro to improve the code readability

The valid values of policy.{min, max} should be between 'min' and 'max',
so use clamp() helper macro to makes cpufreq_verify_within_limits() easier
to follow.

Signed-off-by: Liao Chang <liaochang1@huawei.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Liao Chang

include/linux/cpufreq.h

@@ -19,6 +19,7 @@
 #include <linux/pm_qos.h>
 #include <linux/spinlock.h>
 #include <linux/sysfs.h>
+#include <linux/minmax.h>
 
 /*********************************************************************
  *                        CPUFREQ INTERFACE                          *
@@ -467,17 +468,8 @@ static inline void cpufreq_verify_within_limits(struct cpufreq_policy_data *poli
 						unsigned int min,
 						unsigned int max)
 {
-	if (policy->min < min)
-		policy->min = min;
-	if (policy->max < min)
-		policy->max = min;
-	if (policy->min > max)
-		policy->min = max;
-	if (policy->max > max)
-		policy->max = max;
-	if (policy->min > policy->max)
-		policy->min = policy->max;
-	return;
+	policy->max = clamp(policy->max, min, max);
+	policy->min = clamp(policy->min, min, policy->max);
 }
 
 static inline void