of/platform: increase refcount of fwnode

commit 0f8e5651
("of/platform: Propagate firmware node by calling device_set_node()")
use of_fwnode_handle to replace of_node_get, which introduces a side
effect that the refcount is not increased. Then the out of tree
jailhouse hypervisor enable/disable test will trigger kernel dump in
of_overlay_remove, with the following sequence
"
   of_changeset_revert(&overlay_changeset);
   of_changeset_destroy(&overlay_changeset);
   of_overlay_remove(&overlay_id);
"

So increase the refcount to avoid issues.

This patch also release the refcount when releasing amba device to avoid
refcount leakage.

Fixes: 0f8e5651 ("of/platform: Propagate firmware node by calling device_set_node()")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20230821023928.3324283-2-peng.fan@oss.nxp.comSigned-off-by: Rob Herring <robh@kernel.org>

drivers/of/platform.c

@@ -141,7 +141,7 @@ struct platform_device *of_device_alloc(struct device_node *np,
 	}
 
 	/* setup generic device info */
-	device_set_node(&dev->dev, of_fwnode_handle(np));
+	device_set_node(&dev->dev, of_fwnode_handle(of_node_get(np)));
 	dev->dev.parent = parent ? : &platform_bus;
 
 	if (bus_id)
@@ -239,7 +239,7 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
 	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
 
 	/* setup generic device info */
-	device_set_node(&dev->dev, of_fwnode_handle(node));
+	device_set_node(&dev->dev, of_fwnode_handle(of_node_get(node)));
 	dev->dev.parent = parent ? : &platform_bus;
 	dev->dev.platform_data = platform_data;
 	if (bus_id)