drm/amd/powerplay: check whether need to enable thermal control. (v2)

BugLink: http://bugs.launchpad.net/bugs/1546572

In I+A platform(skylake), it is controlled by intel.

v2: integrate Tom's fix
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
(cherry picked from commit cae9b9c8)
Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/gpu/drm/amd/powerplay/eventmgr/eventtasks.c

@@ -418,10 +418,17 @@ int pem_task_create_user_performance_state(struct pp_eventmgr *eventmgr, struct
 int pem_task_initialize_thermal_controller(struct pp_eventmgr *eventmgr, struct pem_event_data *event_data)
 {
 	struct PP_TemperatureRange range;
+
 	range.max = TEMP_RANGE_MAX;
 	range.min = TEMP_RANGE_MIN;
 
-	return phm_start_thermal_controller(eventmgr->hwmgr, &range);
+	if (eventmgr == NULL || eventmgr->platform_descriptor == NULL)
+		return -EINVAL;
+
+	if (phm_cap_enabled(eventmgr->platform_descriptor->platformCaps, PHM_PlatformCaps_ThermalController))
+		return phm_start_thermal_controller(eventmgr->hwmgr, &range);
+
+	return 0;
 }
 
 int pem_task_uninitialize_thermal_controller(struct pp_eventmgr *eventmgr, struct pem_event_data *event_data)