wt_icache: don't lock requests in the IDLE state

Signed-off-by: Alban Gruin <alban.gruin@irit.fr>

src/cache_subsystem/wt_icache.sv

@@ -197,7 +197,7 @@ end else begin : gen_piton_offset
           // wait for incoming requests
           end else begin
             // mem requests are for sure invals here
-            if (!mem_rtrn_vld_i && !stall_req_i) begin
+            if (!mem_rtrn_vld_i) begin
               dreq_o.ready = 1'b1;
               // we have a new request
               if (dreq_i.req) begin