SoftwareInventory: Implement Bios Related Item

Was a TODO here with the code commented out.

Bios was implemented here:
https://github.com/openbmc/bmcweb/commit/d82a3acd1abc04a13f90cef5234416c3e18da0e1

Tested: Ran validator
curl -k https://${bmc}/redfish/v1/UpdateService/FirmwareInventory/9f75c5ad
{
  "@odata.id": "/redfish/v1/UpdateService/FirmwareInventory/9f75c5ad",
  "@odata.type": "#SoftwareInventory.v1_1_0.SoftwareInventory",
  "Description": "Host image",
  "Id": "9f75c5ad",
  "Members@odata.count": 1,
  "Name": "Software Inventory",
  "RelatedItem": [
    {
      "@odata.id": "/redfish/v1/Systems/system/Bios"
    }
  ],

Change-Id: Ifa6148731582cdc7f177e38b19f02fea966738fc
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/redfish-core/lib/update_service.hpp b/redfish-core/lib/update_service.hpp
index 00e166e..a47aca2 100644
--- a/redfish-core/lib/update_service.hpp
+++ b/redfish-core/lib/update_service.hpp
@@ -604,12 +604,10 @@
         }
         else if (purpose == fw_util::biosPurpose)
         {
-            // TODO(geissonator) Need BIOS schema support added for this
-            //                   to be valid
-            // nlohmann::json &members = aResp->res.jsonValue["RelatedItem"];
-            // members.push_back(
-            //    {{"@odata.id", "/redfish/v1/Systems/system/BIOS"}});
-            // aResp->res.jsonValue["Members@odata.count"] = members.size();
+            nlohmann::json &members = aResp->res.jsonValue["RelatedItem"];
+            members.push_back(
+                {{"@odata.id", "/redfish/v1/Systems/system/Bios"}});
+            aResp->res.jsonValue["Members@odata.count"] = members.size();
         }
         else
         {