ARM: dts: rockchip: enable gmac for rk3288 boards

Enable gmac interface for rk3288 board dts.
use "okay" not "ok"

Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/dts/rk3288-tinker.dtsi b/arch/arm/dts/rk3288-tinker.dtsi
index ceb4e2b..527493c 100644
--- a/arch/arm/dts/rk3288-tinker.dtsi
+++ b/arch/arm/dts/rk3288-tinker.dtsi
@@ -149,7 +149,7 @@
 	pinctrl-0 = <&rgmii_pins>;
 	tx_delay = <0x30>;
 	rx_delay = <0x10>;
-	status = "ok";
+	status = "okay";
 };
 
 &hdmi {