[usbdev] Remove legacy TODO

Issue #18940 was closed. RTL change was accepted into ES
and has also been verified in FPGA numerous times since.

Signed-off-by: Adrian Lees <[email protected]>

Author: alees24

hw/ip/usbdev/rtl/usb_fs_nb_out_pe.sv

@@ -28,7 +28,6 @@ module usb_fs_nb_out_pe #(
   input  logic                   clk_48mhz_i,
   input  logic                   rst_ni,
   input  logic                   link_reset_i,
-  input  logic                   link_active_i,
   input  logic [6:0]             dev_addr_i,
 
   ////////////////////////
@@ -333,11 +332,6 @@ module usb_fs_nb_out_pe #(
     end
   end
 
-  // TODO(#18940): Use the link state to prevent the FSM from responding to
-  // packets until software is ready.
-  logic unused_link_active_i;
-  assign unused_link_active_i = ^link_active_i;
-
   always_ff @(posedge clk_48mhz_i or negedge rst_ni) begin
     if (!rst_ni) begin
       out_xact_state <= StIdle;

hw/ip/usbdev/rtl/usb_fs_nb_pe.sv

@@ -237,7 +237,6 @@ module usb_fs_nb_pe #(
     .clk_48mhz_i            (clk_48mhz_i),
     .rst_ni                 (rst_ni),
     .link_reset_i           (link_reset_i),
-    .link_active_i          (link_active_i),
     .dev_addr_i             (dev_addr_i),
 
     // endpoint interface