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/arch/arm/include/asm/mach-imx/mxc_i2c.h b/arch/arm/include/asm/mach-imx/mxc_i2c.h
index 81fd981..c016aa7 100644
--- a/arch/arm/include/asm/mach-imx/mxc_i2c.h
+++ b/arch/arm/include/asm/mach-imx/mxc_i2c.h
@@ -42,7 +42,7 @@
 	/*
 	 * board file can use this index to locate which i2c_pads_info is for
 	 * i2c_idle_bus. When pinmux is implement, this entry can be
-	 * discarded. Here we do not use dev->seq, because we do not want to
+	 * discarded. Here we do not use dev_seq(dev), because we do not want to
 	 * export device to board file.
 	 */
 	int index;