ARM: dts: gemini: ssi1328: permit to use gigabit

I believed that gigabit was not working due to unknown missing GPIO.
But the problem was due to Marvell PHY incorrectly setting delay.
Now it is fixed, gigabit works.
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/boot/dts/gemini-ssi1328.dts

@@ -40,10 +40,6 @@ mdio0: mdio {
 		phy0: ethernet-phy@1 {
 			reg = <1>;
 			device_type = "ethernet-phy";
-			/* We lack the knowledge of necessary GPIO to achieve
-			 * Gigabit
-			 */
-			max-speed = <100>;
 		};
 		/* WAN ICPlus IP101A */
 		phy1: ethernet-phy@2 {