dt-bindings: vexpress-sysreg: Add deprecated GPIO provider properties

While the current binding expects a child GPIO node, the old style binding
with GPIO provider properties in the parent vexpress-sysreg node is
still in use. Add the GPIO provider properties as deprecated.

Cc: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220613171809.3928949-1-robh@kernel.org

Documentation/devicetree/bindings/arm/vexpress-sysreg.yaml

@@ -29,6 +29,13 @@ properties:
 
   ranges: true
 
+  gpio-controller:
+    deprecated: true
+
+  "#gpio-cells":
+    deprecated: true
+    const: 2
+
 additionalProperties: false
 
 patternProperties: