arm: mvebu: turris_omnia: Enable networking via ethernet switch

The Turris Omnia contains the Marvell 88E6176 ethernet switch. Add
config options and device tree to enable the support.

Signed-off-by: Marek Mojík <marek.mojik@nic.cz>
Signed-off-by: Marek Behún <kabel@kernel.org>
diff --git a/arch/arm/dts/armada-385-turris-omnia-u-boot.dtsi b/arch/arm/dts/armada-385-turris-omnia-u-boot.dtsi
index 509d6ca..c63a331 100644
--- a/arch/arm/dts/armada-385-turris-omnia-u-boot.dtsi
+++ b/arch/arm/dts/armada-385-turris-omnia-u-boot.dtsi
@@ -35,6 +35,57 @@
 	};
 };
 
+&mdio {
+	switch@10 {
+		mdio {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			sw_phy0: ethernet-phy@0 {
+				reg = <0x0>;
+			};
+
+			sw_phy1: ethernet-phy@1 {
+				reg = <0x1>;
+			};
+
+			sw_phy2: ethernet-phy@2 {
+				reg = <0x2>;
+			};
+
+			sw_phy3: ethernet-phy@3 {
+				reg = <0x3>;
+			};
+
+			sw_phy4: ethernet-phy@4 {
+				reg = <0x4>;
+			};
+		};
+		ports {
+			ports@0 {
+				phy-handle = <&sw_phy0>;
+				phy-mode = "internal";
+			};
+			ports@1 {
+				phy-handle = <&sw_phy1>;
+				phy-mode = "internal";
+			};
+			ports@2 {
+				phy-handle = <&sw_phy2>;
+				phy-mode = "internal";
+			};
+			ports@3 {
+				phy-handle = <&sw_phy3>;
+				phy-mode = "internal";
+			};
+			ports@4 {
+				phy-handle = <&sw_phy4>;
+				phy-mode = "internal";
+			};
+		};
+	};
+};
+
 #ifdef CONFIG_ENV_IS_IN_SPI_FLASH
 &spi0 {
 	flash@0 {
diff --git a/configs/turris_omnia_defconfig b/configs/turris_omnia_defconfig
index f045dd7..2914840 100644
--- a/configs/turris_omnia_defconfig
+++ b/configs/turris_omnia_defconfig
@@ -95,7 +95,9 @@
 CONFIG_SPI_FLASH_MTD=y
 CONFIG_PHY_MARVELL=y
 CONFIG_PHY_FIXED=y
+CONFIG_DM_DSA=y
 CONFIG_PHY_GIGE=y
+CONFIG_MV88E6XXX=y
 CONFIG_MVNETA=y
 CONFIG_MII=y
 CONFIG_MVMDIO=y