cpu/ rtc/ include/: Remove lingering references to CFG_CMD_* symbols.

Signed-off-by: Jon Loeliger <jdl@freescale.com>
diff --git a/cpu/mpc8xx/serial.c b/cpu/mpc8xx/serial.c
index 6e08b53..68804cc 100644
--- a/cpu/mpc8xx/serial.c
+++ b/cpu/mpc8xx/serial.c
@@ -723,6 +723,6 @@
 {
 	return;
 }
-#endif	/* CFG_CMD_KGDB	*/
+#endif
 
 #endif	/* CONFIG_8xx_CONS_NONE */