m68knommu: allow 4 coldfire serial ports

Fix driver/serial/mcf.c for 4-ports coldfire's (e.g. MCF5484).

Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
diff --git a/drivers/serial/mcf.c b/drivers/serial/mcf.c
index b9f7dfe..b5aaef9 100644
--- a/drivers/serial/mcf.c
+++ b/drivers/serial/mcf.c
@@ -445,7 +445,7 @@
 	.verify_port	= mcf_verify_port,
 };
 
-static struct mcf_uart mcf_ports[3];
+static struct mcf_uart mcf_ports[4];
 
 #define	MCF_MAXPORTS	ARRAY_SIZE(mcf_ports)