ARM: dts: vf610-zii-dev-rev-c: Configure fiber port to 1000BaseX

The SFF soldered onto the board expects the port to use 1000BaseX.  It
makes no sense to have the port set to SGMII, since it doesn't even
support that mode.
Signed-off-by: Chris Healy <cphealy@gmail.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/vf610-zii-dev-rev-c.dts

@@ -164,7 +164,7 @@ port@4 {
 					port@9 {
 						reg = <9>;
 						label = "sff2";
-						phy-mode = "sgmii";
+						phy-mode = "1000base-x";
 						managed = "in-band-status";
 						sfp = <&sff2>;
 					};