dt-binding: eeprom: at24: add vcc-supply property

In some platforms, they disable the power-supply of eeprom due
to power consumption reduction. This patch add vcc-supply property.

Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Documentation/devicetree/bindings/eeprom/at24.yaml

@@ -164,6 +164,10 @@ properties:
     minimum: 1
     maximum: 8
 
+  vcc-supply:
+    description:
+      phandle of the regulator that provides the supply voltage.
+
 required:
   - compatible
   - reg