You can find a kext made by AndyV here. You have to modify its info.plit to mach with your smbios.plist (or modify your smbios.plist to mach the kext).
Put it in your S/L/E or E/E.
I don't know why we have to have smbios.plist AND the kext,but we have to. I ask andy to explain the content of the info.plist but he hasn't answer yet.
You can find the thread here if you want to ask him or thanks him.