Revert "ARC: [plat-axs10x] add Ethernet PHY description in .dts"

This reverts commit 667a490b.

This is needed to get ethernet(stmmac) working in 4.6-rc2 on axs103.

4.5 needed this fix, but apprently stmmac has gained some fixes which
warrant reversal of this.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/boot/dts/axs10x_mb.dtsi

@@ -47,14 +47,6 @@ ethernet@0x18000 {
 			clocks = <&apbclk>;
 			clock-names = "stmmaceth";
 			max-speed = <100>;
-			mdio0 {
-				#address-cells = <1>;
-				#size-cells = <0>;
-				compatible = "snps,dwmac-mdio";
-				phy1: ethernet-phy@1 {
-					reg = <1>;
-				};
-			};
 		};
 
 		ehci@0x40000 {