thermal/drivers/cpufreq_cooling: Remove unused list

There is a list with the purpose of grouping the cpufreq cooling
device together as described in the comments but actually it is
unused, the code evolved since 2012 and the list was no longer needed.

Delete the remaining unused list related code.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20210314111333.16551-5-daniel.lezcano@linaro.org

drivers/thermal/cpufreq_cooling.c

@@ -59,7 +59,6 @@ struct time_in_idle {
  * @cdev: thermal_cooling_device pointer to keep track of the
  *	registered cooling device.
  * @policy: cpufreq policy.
- * @node: list_head to link all cpufreq_cooling_device together.
  * @idle_time: idle time stats
  * @qos_req: PM QoS contraint to apply
  *
@@ -72,16 +71,12 @@ struct cpufreq_cooling_device {
 	unsigned int max_level;
 	struct em_perf_domain *em;
 	struct cpufreq_policy *policy;
-	struct list_head node;
 #ifndef CONFIG_SMP
 	struct time_in_idle *idle_time;
 #endif
 	struct freq_qos_request qos_req;
 };
 
-static DEFINE_MUTEX(cooling_list_lock);
-static LIST_HEAD(cpufreq_cdev_list);
-
 #ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR
 /**
  * get_level: Find the level for a particular frequency
@@ -602,10 +597,6 @@ __cpufreq_cooling_register(struct device_node *np,
 	if (IS_ERR(cdev))
 		goto remove_qos_req;
 
-	mutex_lock(&cooling_list_lock);
-	list_add(&cpufreq_cdev->node, &cpufreq_cdev_list);
-	mutex_unlock(&cooling_list_lock);
-
 	return cdev;
 
 remove_qos_req:
@@ -697,10 +688,6 @@ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
 
 	cpufreq_cdev = cdev->devdata;
 
-	mutex_lock(&cooling_list_lock);
-	list_del(&cpufreq_cdev->node);
-	mutex_unlock(&cooling_list_lock);
-
 	thermal_cooling_device_unregister(cdev);
 	freq_qos_remove_request(&cpufreq_cdev->qos_req);
 	free_idle_time(cpufreq_cdev);