main: Increase timeout for USB configured state

When the timeout was too small, the main function would infinitely
loop around, restarting the board and waiting for the USB interface
to get configured. But since configuration seems to take more than
one second, it rarely succeeded.
Increasing the timeout makes the USB configuration finish in the
first try.

firmware/src_simtrace/main.c

@@ -51,7 +51,7 @@ extern int main( void )
 
     printf("%s", "USB init\n\r");
     while(USBD_GetState() < USBD_STATE_CONFIGURED){
-        if(i >= MAX_USB_ITER) {
+        if(i >= MAX_USB_ITER*3) {
             TRACE_ERROR("Resetting board (USB could not be configured)\n");
             NVIC_SystemReset();
         }