dt-bindings: misc: pci1de4,1: add required reg property for endpoint

The PCI subsystem links an endpoint Device Tree node to its corresponding
pci_dev structure only if the Bus/Device/Function (BDF) encoded in the
'reg' property matches the actual hardware topology.

Add the 'reg' property and mark it as required to ensure proper binding
between the device_node and the pci_dev.

Update the example to reflect this requirement.

Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/b58bfcd957b2270fcf932d463f2db534b2ae1a6d.1766077285.git.andrea.porta@suse.com
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>

Documentation/devicetree/bindings/misc/pci1de4,1.yaml

@@ -25,6 +25,10 @@ properties:
     items:
       - const: pci1de4,1
 
+  reg:
+    maxItems: 1
+    description: The PCI Bus-Device-Function address.
+
   '#interrupt-cells':
     const: 2
     description: |
@@ -101,6 +105,7 @@ unevaluatedProperties: false
 
 required:
   - compatible
+  - reg
   - '#interrupt-cells'
   - interrupt-controller
   - pci-ep-bus@1
@@ -111,8 +116,9 @@ examples:
         #address-cells = <3>;
         #size-cells = <2>;
 
-        rp1@0,0 {
+        dev@0,0 {
             compatible = "pci1de4,1";
+            reg = <0x10000 0x0 0x0 0x0 0x0>;
             ranges = <0x01 0x00 0x00000000  0x82010000 0x00 0x00  0x00 0x400000>;
             #address-cells = <3>;
             #size-cells = <2>;