mfd: rp1: Fix device links when modules disabled

Device links are used to keep track of suppliers and consumers of
resources, adding some control over the ordering of device probes other
than returning -EPROBE_DEFER. The way the RP1 device is created breaks
this mechanism in the rare case that the use of modules has been
completely disabled, thanks to some opimisations within the device link
code.

Fix this glitch by giving the corresponding fwnode a pointer to the
device, taking the opportunity to remove a pointless check on the
validity of the rp1_node pointer.

See: #7018
Signed-off-by: Phil Elwell <phil@raspberrypi.com>

Author: pelwell

drivers/mfd/rp1.c

@@ -340,9 +340,8 @@ static int rp1_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 					rp1_chained_handle_irq);
 	}
 
-	if (rp1_node)
-		of_platform_populate(rp1_node, NULL, NULL, &pcie_pdev->dev);
-
+	of_node_to_fwnode(rp1_node)->dev = rp1->dev;
+	of_platform_populate(rp1_node, NULL, NULL, &pcie_pdev->dev);
 	of_node_put(rp1_node);
 
 	return 0;