dt-bindings: at24: add ROHM BR24G04

Add compatible for ROHM Semiconductor BR24G04 EEPROMs.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Roland Hieber <rhi@pengutronix.de>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>