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/oem/ibm/libpldmresponder/platform_oem_ibm.hpp b/oem/ibm/libpldmresponder/platform_oem_ibm.hpp
index 13ec2d5..e728282 100644
--- a/oem/ibm/libpldmresponder/platform_oem_ibm.hpp
+++ b/oem/ibm/libpldmresponder/platform_oem_ibm.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "pldmd/instance_id.hpp"
+#include "common/instance_id.hpp"
 #include "requester/handler.hpp"
 
 #include <vector>