poplar: enable Ethernet driver support

The 'phy' reset of gmac device in kernel device tree is not generic
enough for u-boot to use, so we need to overwrite the 'resets' property
as needed.  With this device tree fixup and poplar_defconfig changes,
Ethernet starts working on Poplar board.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/arch/arm/dts/hi3798cv200-u-boot.dtsi b/arch/arm/dts/hi3798cv200-u-boot.dtsi
index 7844c52..2de06d9 100644
--- a/arch/arm/dts/hi3798cv200-u-boot.dtsi
+++ b/arch/arm/dts/hi3798cv200-u-boot.dtsi
@@ -8,7 +8,15 @@
  * (C) Copyright 2017 Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
  */
 
+#include <dt-bindings/reset/ti-syscon.h>
+
 &soc {
+	rst: reset-controller@8a22000 {
+		compatible = "hisilicon,hi3798cv200-reset";
+		reg = <0x8a22000 0x1000>;
+		#reset-cells = <3>;
+	};
+
 	usb2: ehci@9890000 {
 		compatible = "generic-ehci";
 		reg = <0x9890000 0x100>;
@@ -16,6 +24,12 @@
 	};
 };
 
+&gmac1 {
+	resets = <&rst 0xcc 9  ASSERT_SET>,
+		 <&rst 0xcc 11 ASSERT_SET>,
+		 <&rst 0xcc 13 DEASSERT_SET>;
+};
+
 &uart0 {
 	clock = <75000000>;
 	status = "okay";