InstanceIdDb: Move header from pldmd/ to common/

The header is used across all executables produced by the project, which
makes it "common".

Change-Id: I022b179fad1de8dba2ef39fd33bc240ec73a2d33
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/requester/test/handler_test.cpp b/requester/test/handler_test.cpp
index 6251974..17a40fe 100644
--- a/requester/test/handler_test.cpp
+++ b/requester/test/handler_test.cpp
@@ -1,7 +1,7 @@
+#include "common/instance_id.hpp"
 #include "common/types.hpp"
 #include "common/utils.hpp"
 #include "mock_request.hpp"
-#include "pldmd/instance_id.hpp"
 #include "requester/handler.hpp"
 #include "test/test_instance_id.hpp"