cpu/m*: Remove obsolete references to CONFIG_COMMANDS

Signed-off-by: Jon Loeliger <jdl@freescale.com>
diff --git a/cpu/mpc8xx/serial.c b/cpu/mpc8xx/serial.c
index 62af129..6e08b53 100644
--- a/cpu/mpc8xx/serial.c
+++ b/cpu/mpc8xx/serial.c
@@ -666,7 +666,7 @@
 }
 #endif
 
-#if (CONFIG_COMMANDS & CFG_CMD_KGDB) || defined(CONFIG_CMD_KGDB)
+#if defined(CONFIG_CMD_KGDB)
 
 void
 kgdb_serial_init(void)