ARM: dts: imx6: RDU2: Add Switch EEPROM

The Marvell switch has an EEPROM connected to it. List the size in DT,
in order to enable access to it via ethtool.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Chris Healy <cphealy@gmail.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-zii-rdu2.dtsi

@@ -636,6 +636,7 @@ switch@0 {
 			#size-cells = <0>;
 			reg = <0>;
 			dsa,member = <0 0>;
+			eeprom-length = <512>;
 
 			ports {
 				#address-cells = <1>;