Mechanism to associate sensor/effecter to FRU entity

The "entity_path" key is defined in PDR JSONs and will have an FRU D-Bus object
path as the value, if this is present, the entity type, instance, and container
id should be associate with the FRU entity.

Tested: test JSON with https://gist.github.com/lxwinspur/7225a9301ccfcbff1f6549203405b4fa
after executing the following command, get the entity information from FruHandler
entity_type = 120
entity_instance_num = 1
entity_container_id = 0

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: I019f9a0b9d4dbec20a71dfd797f30ac8f57f67b8
diff --git a/libpldmresponder/fru.cpp b/libpldmresponder/fru.cpp
index cb7d5f7..2555a97 100644
--- a/libpldmresponder/fru.cpp
+++ b/libpldmresponder/fru.cpp
@@ -93,6 +93,8 @@
 
                     auto recordInfos = parser.getRecordInfo(interface.first);
                     populateRecords(interfaces, recordInfos, entity);
+
+                    associatedEntityMap.emplace(object.first, entity);
                     break;
                 }
                 catch (const std::exception& e)