of: Always use 'struct device.of_node' to get device node pointer.

The following structure elements duplicate the information in
'struct device.of_node' and so are being eliminated.  This patch
makes all readers of these elements use device.of_node instead.

(struct of_device *)->node
(struct dev_archdata *)->prom_node (sparc)
(struct dev_archdata *)->of_node (powerpc & microblaze)

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c
index 7d521e1..1db114b 100644
--- a/drivers/gpio/pca953x.c
+++ b/drivers/gpio/pca953x.c
@@ -437,7 +437,7 @@
 	struct device_node *node;
 	const uint16_t *val;
 
-	node = dev_archdata_get_node(&client->dev.archdata);
+	node = client->dev.of_node;
 	if (node == NULL)
 		return NULL;