zone: Add debug thermal/power interface

- Add xyz.openbmc_project.Debug.Pid.ThermalPower interface to
  fanctrl/zoneX/pid dbus to record some datas in thermal/power
  PID loop.

Tested:
```
busctl introspect xyz.openbmc_project.State.FanCtrl /xyz/openbmc_project/settings/fanctrl/zone0/CPU0_PID xyz.openbmc_project.Debug.Pid.ThermalPower
NAME                                       TYPE      SIGNATURE RESULT/VALUE  FLAGS
.ClassType                                 property  s         "Temperature" emits-change
.Input                                     property  d         36.594        emits-change
.Leader                                    property  s         "Die_CPU0"    emits-change
.Output                                    property  d         4200          emits-change
.Setpoint                                  property  d         70            emits-change
```

Signed-off-by: Harvey Wu <Harvey.Wu@quantatw.com>
Change-Id: I6846c3878c2ca5eaeeb6eaf48aaf0f604a2beccf
diff --git a/test/zone_mock.hpp b/test/zone_mock.hpp
index ba167f4..8ba9c85 100644
--- a/test/zone_mock.hpp
+++ b/test/zone_mock.hpp
@@ -51,6 +51,10 @@
 
     MOCK_METHOD0(initializeLog, void());
     MOCK_METHOD1(writeLog, void(const std::string&));
+
+    MOCK_METHOD4(updateThermalPowerDebugInterface,
+                 void(std::string pidName, std::string leader, double input,
+                      double output));
 };
 
 } // namespace pid_control