Add support for System Airflow sensor

Added DBUS object path for Airflow sensor to get the system airflow
sensor. This fix requires following fix dbus-sensors
https://gerrit.openbmc-project.xyz/c/openbmc/dbus-sensors/+/45241

Tested: Checked redfish/v1/Chassis/<chassis_id>/Sensors/
System_Airflow  displayed the correct values.

Signed-off-by: Basheer Ahmed Muddebihal <basheerx.muddebihal@intel.com>
Change-Id: I32134e659a9fa7a5357fe5928ecebc0fc121c2bc
diff --git a/redfish-core/lib/sensors.hpp b/redfish-core/lib/sensors.hpp
index d986565..cb7ea15 100644
--- a/redfish-core/lib/sensors.hpp
+++ b/redfish-core/lib/sensors.hpp
@@ -63,6 +63,7 @@
              {node::sensors,
               {"/xyz/openbmc_project/sensors/power",
                "/xyz/openbmc_project/sensors/current",
+               "/xyz/openbmc_project/sensors/airflow",
                "/xyz/openbmc_project/sensors/utilization"}},
              {node::thermal,
               {"/xyz/openbmc_project/sensors/fan_tach",