ARM: shmobile: silk: add Ether DT support

Define the SILK board dependent part of the Ether device node.
Enable DHCP and NFS root for the kernel booting.

Based on the original patch by Vladimir Barinov
<vladimir.barinov@cogentembedded.com>.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
diff --git a/arch/arm/boot/dts/r8a7794-silk.dts b/arch/arm/boot/dts/r8a7794-silk.dts
index f3da95b..79bc64b 100644
--- a/arch/arm/boot/dts/r8a7794-silk.dts
+++ b/arch/arm/boot/dts/r8a7794-silk.dts
@@ -22,7 +22,7 @@
 	};
 
 	chosen {
-		bootargs = "ignore_loglevel";
+		bootargs = "ignore_loglevel rw root=/dev/nfs ip=dhcp";
 		stdout-path = &scif2;
 	};
 
@@ -41,6 +41,16 @@
 		renesas,groups = "scif2_data";
 		renesas,function = "scif2";
 	};
+
+	ether_pins: ether {
+		renesas,groups = "eth_link", "eth_mdio", "eth_rmii";
+		renesas,function = "eth";
+	};
+
+	phy1_pins: phy1 {
+		renesas,groups = "intc_irq8";
+		renesas,function = "intc";
+	};
 };
 
 &scif2 {
@@ -49,3 +59,19 @@
 
 	status = "okay";
 };
+
+&ether {
+	pinctrl-0 = <&ether_pins &phy1_pins>;
+	pinctrl-names = "default";
+
+	phy-handle = <&phy1>;
+	renesas,ether-link-active-low;
+	status = "okay";
+
+	phy1: ethernet-phy@1 {
+		reg = <1>;
+		interrupt-parent = <&irqc0>;
+		interrupts = <8 IRQ_TYPE_LEVEL_LOW>;
+		micrel,led-mode = <1>;
+	};
+};