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>