[EXAMPLES] Ported the mojo counter example to Zynq ZED board.

Will be adding a tutorial on this to verilog.james.walms.co.uk in a few days.

techlibs/xilinx/example_zed_counter/example.v

@@ -0,0 +1,14 @@
+module top(clk, ctrl, led_7, led_6, led_5, led_4, led_3, led_2, led_1, led_0);
+
+input clk, ctrl;
+output led_7, led_6, led_5, led_4;
+output led_3, led_2, led_1, led_0;
+
+reg [31:0] counter;
+
+always @(posedge clk)
+	counter <= counter + (ctrl ? 4 : 1);
+
+assign {led_7, led_6, led_5, led_4, led_3, led_2, led_1, led_0} = counter >> 24;
+
+endmodule