MAINTAINERS: add I2C DT bindings to ARM platforms

Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>