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/handler.hpp b/requester/handler.hpp
index b03e05d..9e5d8d1 100644
--- a/requester/handler.hpp
+++ b/requester/handler.hpp
@@ -1,7 +1,7 @@
 #pragma once
 
+#include "common/instance_id.hpp"
 #include "common/types.hpp"
-#include "pldmd/instance_id.hpp"
 #include "request.hpp"
 
 #include <libpldm/base.h>