emacps: Fix error when multiple PCSPMA IP are instantiated

[patocarr]

Details on this post:
https://forums.xilinx.com/t5/Embedded-Linux/Petalinux-2020-1-fails-to-generate-default-device-tree-but-works/td-p/1119777

[IsaacJT]

I can confirm that this fixes the compile error but the device tree that comes out isn't quite correct with 2 x PCS/PMA blocks:

&gem0 {
	phy-handle = <&phy7>;
	phy-mode = "gmii";
	status = "okay";
	xlnx,ptp-enet-clock = <0x0>;
};
&gem1 {
	phy-handle = <&phy7>;
	phy-mode = "gmii";
	status = "okay";
	xlnx,ptp-enet-clock = <0x0>;
	phy7: phy@7 {
		reg = <0x07>;
		xlnx,phy-type = <0x5>;
	};
};

It only creates one PHY node and connects both GEMs to the one node. They should each have their own node and appropriate handles.

EDIT: This is easy to fix in the system-user.dtsi but could be a trap for people who aren't aware of it