checks: Allow PCI bridge child nodes without an address

Some PCI bridge nodes have child nodes such as an interrupt controller
which are not PCI devices. Allow these nodes which don't have a
unit-address.

Signed-off-by: Rob Herring <robh@kernel.org>
Message-Id: <20200928201942.3242124-1-robh@kernel.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

checks.c

@@ -891,10 +891,8 @@ static void check_pci_device_reg(struct check *c, struct dt_info *dti, struct no
 		return;
 
 	prop = get_property(node, "reg");
-	if (!prop) {
-		FAIL(c, dti, node, "missing PCI reg property");
+	if (!prop)
 		return;
-	}
 
 	cells = (cell_t *)prop->val.val;
 	if (cells[1] || cells[2])