Add new PID Class types "power" and "powersum"

Implements this feature:
https://github.com/openbmc/phosphor-pid-control/issues/24

In addition to the existing "temp" and "margin" classes, adding
new "power" and "powersum" Class types.

The "power" class is the same as "temp", but expects D-Bus power
sensors, instead of D-Bus temperature sensors.

The "powersum" class is the same as "power", but sums together all of
the given inputs, instead of finding the maximum.

Signed-off-by: Josh Lehan <krellan@google.com>
Change-Id: I11d8ad8385632658ed061671134be87a560cd02a
diff --git a/dbus/dbusconfiguration.cpp b/dbus/dbusconfiguration.cpp
index 460e9e3..29f0ccb 100644
--- a/dbus/dbusconfiguration.cpp
+++ b/dbus/dbusconfiguration.cpp
@@ -646,7 +646,8 @@
                     // All non-fan PID classes should be initialized this way.
                     // As for why a fan should not use this code path, see
                     // the ed1dafdf168def37c65bfb7a5efd18d9dbe04727 commit.
-                    if ((pidClass == "temp") || (pidClass == "margin"))
+                    if ((pidClass == "temp") || (pidClass == "margin") ||
+                        (pidClass == "power") || (pidClass == "powersum"))
                     {
                         std::string inputSensorName =
                             getSensorNameFromPath(inputSensorPath);