86xx: Fix lingering CFG_CMD_* references in sbc8641d.h

Remove a leftover in net/tftp.c while we're at it.

Signed-off-by: Jon Loeliger <jdl@freescale.com>
diff --git a/net/tftp.c b/net/tftp.c
index 888ec98..d6db91c 100644
--- a/net/tftp.c
+++ b/net/tftp.c
@@ -614,4 +614,4 @@
 
 #endif /* Multicast TFTP */
 
-#endif /* CFG_CMD_NET */
+#endif