Fix compile error in building MBX860T.

Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/cpu/mpc8xx/cpu.c b/cpu/mpc8xx/cpu.c
index 40f81ef..2eb848b 100644
--- a/cpu/mpc8xx/cpu.c
+++ b/cpu/mpc8xx/cpu.c
@@ -644,7 +644,7 @@
  */
 int cpu_eth_init(bd_t *bis)
 {
-#if defined(SCC_ENET)
+#if defined(SCC_ENET) && defined(CONFIG_CMD_NET)
 	scc_initialize(bis);
 #endif
 #if defined(FEC_ENET)