adding stream arbiter

hw/rtl/libs/VX_priority_encoder.v

@@ -1,11 +1,12 @@
 `include "VX_platform.vh"
 
 module VX_priority_encoder #( 
-    parameter N = 1
+    parameter N    = 1,
+    parameter LOGN = `LOG2UP(N)
 ) (
-    input  wire [N-1:0]          data_in,
-    output wire [`LOG2UP(N)-1:0] data_out,
-    output wire                  valid_out
+    input  wire [N-1:0]    data_in,
+    output wire [LOGN-1:0] data_out,
+    output wire            valid_out
 );    
     reg [`LOG2UP(N)-1:0] data_out_r;
 
@@ -13,7 +14,7 @@ module VX_priority_encoder #(
         data_out_r = 0;
         for (integer i = 0; i < N; i++) begin
             if (data_in[i]) begin
-                data_out_r = `LOG2UP(N)'(i);
+                data_out_r = LOGN'(i);
                 break;
             end
         end