dt-bindings: eeprom: at24: add "atmel,24c2048" compatible string

Add new compatible to the device tree bindings.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

Documentation/devicetree/bindings/eeprom/at24.txt

@@ -27,6 +27,7 @@ Required properties:
                 "atmel,24c256",
                 "atmel,24c512",
                 "atmel,24c1024",
+                "atmel,24c2048",
 
                 If <manufacturer> is not "atmel", then a fallback must be used
                 with the same <model> and "atmel" as manufacturer.