dt-bindings: eeprom: at24: Add compatible for Puya P24C256C

Add the compatible for an 256Kb EEPROM from Puya.

Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250103-fp5-cam-eeprom-v1-3-88dee1b36f8e@fairphone.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: lweiss-fairphone

Documentation/devicetree/bindings/eeprom/at24.yaml

@@ -138,6 +138,10 @@ properties:
               - renesas,r1ex24128
               - samsung,s524ad0xd1
           - const: atmel,24c128
+      - items:
+          - enum:
+              - puya,p24c256c
+          - const: atmel,24c256
       - items:
           - const: microchip,24aa025e48
       - items: