dm: Avoid accessing seq directly

At present various drivers etc. access the device's 'seq' member directly.
This makes it harder to change the meaning of that member. Change access
to go through a function instead.

The drivers/i2c/lpc32xx_i2c.c file is left unchanged for now.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/serial/serial_mcf.c b/drivers/serial/serial_mcf.c
index a78a7ec..4ba6dc3 100644
--- a/drivers/serial/serial_mcf.c
+++ b/drivers/serial/serial_mcf.c
@@ -85,7 +85,7 @@
 {
 	struct coldfire_serial_plat *plat = dev->plat;
 
-	plat->port = dev->seq;
+	plat->port = dev_seq(dev);
 
 	return mcf_serial_init_common((uart_t *)plat->base,
 						plat->port, plat->baudrate);