dm: core: Replace of_offset with accessor (part 2)

At present devices use a simple integer offset to record the device tree
node associated with the device. In preparation for supporting a live
device tree, which uses a node pointer instead, refactor existing code to
access this field through an inline function.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/atmel_hlcdfb.c b/drivers/video/atmel_hlcdfb.c
index 903653f..47078fd 100644
--- a/drivers/video/atmel_hlcdfb.c
+++ b/drivers/video/atmel_hlcdfb.c
@@ -497,7 +497,7 @@
 {
 	struct atmel_hlcdc_priv *priv = dev_get_priv(dev);
 	const void *blob = gd->fdt_blob;
-	int node = dev->of_offset;
+	int node = dev_of_offset(dev);
 
 	priv->regs = (struct atmel_hlcd_regs *)devfdt_get_addr(dev);
 	if (!priv->regs) {
@@ -505,7 +505,7 @@
 		return -EINVAL;
 	}
 
-	if (fdtdec_decode_display_timing(blob, dev->of_offset,
+	if (fdtdec_decode_display_timing(blob, dev_of_offset(dev),
 					 0, &priv->timing)) {
 		debug("%s: Failed to decode display timing\n", __func__);
 		return -EINVAL;