fib: Move the adjacency midchain nodes into a separate file

Type: refactor

It's only the nodes that require compiling for each arch,

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: Ibb2bfc756001735cc10ef0fd8db7e8b8358cf8e2
diff --git a/src/vnet/adj/adj_internal.h b/src/vnet/adj/adj_internal.h
index 253c1e9..3dbf7e2 100644
--- a/src/vnet/adj/adj_internal.h
+++ b/src/vnet/adj/adj_internal.h
@@ -42,6 +42,14 @@
 #define ADJ_DBG(_e, _fmt, _args...)
 #endif
 
+/*
+ * Vlib nodes
+ */
+extern vlib_node_registration_t adj_nsh_midchain_node;
+extern vlib_node_registration_t adj_nsh_rewrite_node;
+extern vlib_node_registration_t adj_midchain_tx_no_count_node;
+extern vlib_node_registration_t adj_midchain_tx_node;
+
 static inline u32
 adj_get_rewrite_node (vnet_link_t linkt)
 {