driver core / ACPI: Represent ACPI companions using fwnode_handle

Now that we have struct fwnode_handle, we can use that to point to
ACPI companions from struct device objects instead of pointing to
struct acpi_device directly.

There are two benefits from that.  First, the somewhat ugly and
hackish struct acpi_dev_node can be dropped and, second, the same
struct fwnode_handle pointer can be used in the future to point
to other (non-ACPI) firmware device node types.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 9421fed..17f0204 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -454,7 +454,7 @@
 		goto err_alloc;
 
 	pdev->dev.parent = pdevinfo->parent;
-	ACPI_COMPANION_SET(&pdev->dev, pdevinfo->acpi_node.companion);
+	pdev->dev.fwnode = pdevinfo->fwnode;
 
 	if (pdevinfo->dma_mask) {
 		/*