Add associations for pwm

Pwm doesn't inheirt from Sensor as it is special, so
it needs it to be added seperate.

Tested: Saw associations on dbus

Change-Id: I2178e9346dcae845b47a013a2cc15f62e9ed9b31
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/src/PwmSensor.cpp b/src/PwmSensor.cpp
index 047d5ea..b157d52 100644
--- a/src/PwmSensor.cpp
+++ b/src/PwmSensor.cpp
@@ -13,7 +13,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 */
-#include <PwmSensor.hpp>
+#include "PwmSensor.hpp"
+
+#include "Utils.hpp"
+
 #include <fstream>
 #include <iostream>
 #include <sdbusplus/asio/object_server.hpp>
@@ -22,7 +25,8 @@
 static constexpr size_t pwmMin = 0;
 
 PwmSensor::PwmSensor(const std::string& sysPath,
-                     sdbusplus::asio::object_server& objectServer) :
+                     sdbusplus::asio::object_server& objectServer,
+                     const std::string& sensorConfiguration) :
     sysPath(sysPath),
     objectServer(objectServer)
 {
@@ -106,6 +110,11 @@
         });
     sensorInterface->initialize();
     controlInterface->initialize();
+
+    association = objectServer.add_interface(
+        "/xyz/openbmc_project/sensors/fan_pwm/" + name,
+        "org.openbmc.Associations");
+    createAssociation(association, sensorConfiguration);
 }
 PwmSensor::~PwmSensor()
 {