vpnor: Rename mboxd_pnor_partition_table sources to backend

Change-Id: I6f0fff4ab54e011c1765fc04186e899754787641
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/vpnor/pnor_partition.hpp b/vpnor/pnor_partition.hpp
index c91f22e..681f013 100644
--- a/vpnor/pnor_partition.hpp
+++ b/vpnor/pnor_partition.hpp
@@ -4,7 +4,7 @@
 
 extern "C" {
 #include "backend.h"
-#include "mboxd_pnor_partition_table.h"
+#include "vpnor/backend.h"
 };
 
 #include "pnor_partition_table.hpp"