[reggen] Convert addrmiss to comb logic

`addrmiss` was `always_ff` from `addr_hit`. It results in visible to
next transaction. Now it is changed to combinational logic to in-phase
with the request and response.

This is related to #246.

util/reggen/reg_top.tpl.sv

diff --git a/util/reggen/reg_top.tpl.sv b/util/reggen/reg_top.tpl.sv
index c2b6499..a0fa793 100644
--- a/util/reggen/reg_top.tpl.sv
+++ b/util/reggen/reg_top.tpl.sv
@@ -245,13 +245,7 @@
     % endfor
   end
 
-  always_ff @(posedge clk_i or negedge rst_ni) begin
-    if (!rst_ni) begin
-      addrmiss <= 1'b0;
-    end else if (reg_re || reg_we) begin
-      addrmiss <= ~|addr_hit;
-    end
-  end
+  assign addrmiss = (reg_re || reg_we) ? ~|addr_hit : 1'b0 ;
 
   // Check sub-word write is permitted
   always_comb begin