Revert "ethernet: xilinx: Add ACP Port support"

This reverts commit a63c09eb.
For ACP port based designs if we use the dma-coherent;
flag in the dts file the mapped memory is cacheable and no need of this patch.

Example DT Node:
axi_10g_ethernet_0_ten_gig_eth_mac: ten-gig-eth-mac@43c10000 {
	axistream-connected = <&axi_dma_0>;
	compatible = "xlnx,ten-gig-eth-mac";
	reg = <0x43c10000 0x10000>;
	local-mac-address = [00 0a 35 00 00 00];
	interrupt-parent = <&ps7_scugic_0>;
	interrupts = <0 33 1>;
	xlnx,phy-type = <0x6>;
	xlnx,rxmem = <0x8000>;
	dma-coherent;
};

Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>