wip: basic pixel generator + coordinator module

coordinator is a high level hub75 controller.
It drives multiple panels by generating the x/y coordinates that would
be displayed on each, then converting those into the BRAM format to be
written quickly.

verilog/tb/coordinator_tb.sv

@@ -0,0 +1,14 @@
+`timescale 1ns / 100ps  // 1 ns time unit, 100 ps resolution
+
+module coordinator_tb();
+reg clk = 0;
+coordinator dut(.clk(clk));
+  always #8 clk = !clk;
+  initial begin
+    $dumpfile("coordinator.vcd");
+    $dumpvars(0, coordinator_tb);
+    repeat (10000) @(posedge clk);
+    $finish;
+  end
+endmodule
+