ARM: cfa10036: dt: Change i2c0 clock frequency

The OLED display can work faster. Change the i2c controller clock
frequency to remove the tearing effect that can be seen on the display.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx28-cfa10036.dts

@@ -67,6 +67,7 @@ duart: serial@80074000 {
 			i2c0: i2c@80058000 {
 				pinctrl-names = "default";
 				pinctrl-0 = <&i2c0_pins_b>;
+				clock-frequency = <400000>;
 				status = "okay";
 
 				ssd1306: oled@3c {