ARM: dts: rockchip: disable gmac by default in rk3288.dtsi

This block should not be enabled by default or else if the kconfig is set,
it will try to load/probe even if there's no phy connected.
Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm/boot/dts/rk3288.dtsi

@@ -411,6 +411,7 @@ gmac: ethernet@ff290000 {
 			"mac_clk_rx", "mac_clk_tx",
 			"clk_mac_ref", "clk_mac_refout",
 			"aclk_mac", "pclk_mac";
+		status = "disabled";
 	};
 
 	usb_host0_ehci: usb@ff500000 {