of/address: Introduce of_get_next_dma_parent() helper

Add of_get_next_dma_parent() helper which is similar to
__of_get_dma_parent(), but can be used in iterators and decrements the
ref count on the prior parent.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of/address.c

@@ -695,6 +695,16 @@ static struct device_node *__of_get_dma_parent(const struct device_node *np)
 	return of_node_get(args.np);
 }
 
+static struct device_node *of_get_next_dma_parent(struct device_node *np)
+{
+	struct device_node *parent;
+
+	parent = __of_get_dma_parent(np);
+	of_node_put(np);
+
+	return parent;
+}
+
 u64 of_translate_dma_address(struct device_node *dev, const __be32 *in_addr)
 {
 	struct device_node *host;