thermal: debug: add debug statement for core and step_wise

To ease debugging thermal problem, add these dynamic debug statements
so that user do not need rebuild kernel to see these info.

Based on a patch from Zhang Rui for debugging on bugzilla:
https://bugzilla.kernel.org/attachment.cgi?id=98671

A sample output after we turn on dynamic debug with the following cmd:
# echo 'module thermal_sys +fp' > /sys/kernel/debug/dynamic_debug/control
is like:

[  355.147627] update_temperature: thermal thermal_zone0: last_temperature=52000, current_temperature=55000
[  355.147636] thermal_zone_trip_update: thermal thermal_zone0: Trip1[type=1,temp=79000]:trend=2,throttle=0
[  355.147644] get_target_state: thermal cooling_device8: cur_state=0
[  355.147647] thermal_zone_trip_update: thermal cooling_device8: old_target=-1, target=-1
[  355.147652] get_target_state: thermal cooling_device7: cur_state=0
[  355.147655] thermal_zone_trip_update: thermal cooling_device7: old_target=-1, target=-1
[  355.147660] get_target_state: thermal cooling_device6: cur_state=0
[  355.147663] thermal_zone_trip_update: thermal cooling_device6: old_target=-1, target=-1
[  355.147668] get_target_state: thermal cooling_device5: cur_state=0
[  355.147671] thermal_zone_trip_update: thermal cooling_device5: old_target=-1, target=-1
[  355.147678] thermal_zone_trip_update: thermal thermal_zone0: Trip2[type=0,temp=90000]:trend=1,throttle=0
[  355.147776] get_target_state: thermal cooling_device0: cur_state=0
[  355.147783] thermal_zone_trip_update: thermal cooling_device0: old_target=-1, target=-1
[  355.147792] thermal_zone_trip_update: thermal thermal_zone0: Trip3[type=0,temp=80000]:trend=1,throttle=0
[  355.147845] get_target_state: thermal cooling_device1: cur_state=0
[  355.147849] thermal_zone_trip_update: thermal cooling_device1: old_target=-1, target=-1
[  355.147856] thermal_zone_trip_update: thermal thermal_zone0: Trip4[type=0,temp=70000]:trend=1,throttle=0
[  355.147904] get_target_state: thermal cooling_device2: cur_state=0
[  355.147908] thermal_zone_trip_update: thermal cooling_device2: old_target=-1, target=-1
[  355.147915] thermal_zone_trip_update: thermal thermal_zone0: Trip5[type=0,temp=60000]:trend=1,throttle=0
[  355.147963] get_target_state: thermal cooling_device3: cur_state=0
[  355.147967] thermal_zone_trip_update: thermal cooling_device3: old_target=-1, target=-1
[  355.147973] thermal_zone_trip_update: thermal thermal_zone0: Trip6[type=0,temp=55000]:trend=1,throttle=1
[  355.148022] get_target_state: thermal cooling_device4: cur_state=0
[  355.148025] thermal_zone_trip_update: thermal cooling_device4: old_target=-1, target=1
[  355.148036] thermal_cdev_update: thermal cooling_device4: zone0->target=1
[  355.169279] thermal_cdev_update: thermal cooling_device4: set to state 1

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c
index d89e781..f251521 100644
--- a/drivers/thermal/step_wise.c
+++ b/drivers/thermal/step_wise.c
@@ -60,6 +60,7 @@
 	 */
 	cdev->ops->get_cur_state(cdev, &cur_state);
 	next_target = instance->target;
+	dev_dbg(&cdev->device, "cur_state=%ld\n", cur_state);
 
 	switch (trend) {
 	case THERMAL_TREND_RAISING:
@@ -131,6 +132,9 @@
 	if (tz->temperature >= trip_temp)
 		throttle = true;
 
+	dev_dbg(&tz->device, "Trip%d[type=%d,temp=%ld]:trend=%d,throttle=%d\n",
+				trip, trip_type, trip_temp, trend, throttle);
+
 	mutex_lock(&tz->lock);
 
 	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
@@ -139,6 +143,8 @@
 
 		old_target = instance->target;
 		instance->target = get_target_state(instance, trend, throttle);
+		dev_dbg(&instance->cdev->device, "old_target=%d, target=%d\n",
+					old_target, (int)instance->target);
 
 		if (old_target == instance->target)
 			continue;