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/spi/zynq_qspi.c b/drivers/spi/zynq_qspi.c
index c2ae4e9..2fc28b6 100644
--- a/drivers/spi/zynq_qspi.c
+++ b/drivers/spi/zynq_qspi.c
@@ -568,7 +568,7 @@
 	priv->len = bitlen / 8;
 
 	debug("zynq_qspi_xfer: bus:%i cs:%i bitlen:%i len:%i flags:%lx\n",
-	      bus->seq, slave_plat->cs, bitlen, priv->len, flags);
+	      dev_seq(bus), slave_plat->cs, bitlen, priv->len, flags);
 
 	/*
 	 * Festering sore.