ARM: UniPhier: set I2C offset length of on-board EEPROM in DTS

The EEPROM chips on UniPhier reference daughter boards expect 2-byte
offset address.

Since 7132b9fd68 (dm: i2c: dts: Support an offset-len device tree
property), I2C sub-nodes can have "u-boot,i2c-offset-len" property.

It is convenient to set the default I2C offset address length in
Device Tree, so that we do not have to set it on the command line.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

arch/arm/dts/uniphier-ref-daughter.dtsi

@@ -11,5 +11,6 @@
 	eeprom {
 		compatible = "i2c-eeprom";
 		reg = <0x50>;
+		u-boot,i2c-offset-len = <2>;
 	};
 };