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>