Implement processor throttle dbus properties

- create processor throttle dbus objects for each OCC (processor)
- update throttle properties based on OCC poll response data
  or safe mode status.

Throttle data will be made available via Redfish

NAME                                       TYPE      SIGNATURE RESULT/VALUE FLAGS
org.freedesktop.DBus.Introspectable        interface -         -            -
.Introspect                                method    -         s            -
org.freedesktop.DBus.Peer                  interface -         -            -
.GetMachineId                              method    -         s            -
.Ping                                      method    -         -            -
org.freedesktop.DBus.Properties            interface -         -            -
.Get                                       method    ss        v            -
.GetAll                                    method    s         a{sv}        -
.Set                                       method    ssv       -            -
.PropertiesChanged                         signal    sa{sv}as  -            -
xyz.openbmc_project.Control.Power.Throttle interface -         -            -
.ThrottleCauses                            property  as        0            emits-change
.Throttled                                 property  b         false        emits-change

Example of throttled processor (due to a power limit):
as 1 "xyz.openbmc_project.Control.Power.Throttle.ThrottleReasons.PowerLimit"

Change-Id: I0af9d82fab9d694427d0adaa45f4a372d25fbc12
Signed-off-by: Chris Cain <cjcain@us.ibm.com>
diff --git a/app.cpp b/app.cpp
index a7e5f63..1d0ece3 100644
--- a/app.cpp
+++ b/app.cpp
@@ -37,6 +37,7 @@
     // Attach the bus to sd_event to service user requests
     bus.attach_event(eventP.get(), SD_EVENT_PRIORITY_NORMAL);
 
+    // Add object manager interfaces (for mapper)
     sdbusplus::server::manager_t objManager(bus, OCC_CONTROL_ROOT);
 #ifdef READ_OCC_SENSORS
     sdbusplus::server::manager_t objManagerXyz(bus, OCC_SENSORS_ROOT);
@@ -45,6 +46,8 @@
     sdbusplus::server::manager_t objManagerXyzControl(
         bus, "/xyz/openbmc_project/control");
 #endif
+    sdbusplus::server::manager_t objManagerXyzInventory(
+        bus, "/xyz/openbmc_project/inventory");
     open_power::occ::Manager mgr(eventP);
 
     // Claim the bus since all the house keeping is done now