For each zone log sensor name with max setpoint

Add sensor name that has the maximum setpoint for a PID zone.
Log a debug message when the sensor is changed.
The name is also added to the log file for each log record.

Tested:
Override one CPU temperature sensor
busctl set-property xyz.openbmc_project.CPUSensor /xyz/openbmc_project/sensors/temperature/DTS_CPU1 xyz.openbmc_project.Sensor.Value Value d 82
Observed log message:
swampd[443]: PID Zone 0 max SetPoint 34.5546 requested by DTS_CPU1

Signed-off-by: Nirav Shah <nirav.j2.shah@intel.com>
Signed-off-by: Zhikui Ren <zhikui.ren@intel.com>
Change-Id: Ifc12cb9a106da1bf41dd35697210f74ba1b589db
diff --git a/pid/stepwisecontroller.cpp b/pid/stepwisecontroller.cpp
index c8ec219..5c36778 100644
--- a/pid/stepwisecontroller.cpp
+++ b/pid/stepwisecontroller.cpp
@@ -101,7 +101,7 @@
     }
     else
     {
-        _owner->addSetPoint(value);
+        _owner->addSetPoint(value, _id);
     }
     return;
 }