* add WATCHDOG_RESET to !tstc() loops
* prevents watchdog timeout, while waiting for input,
  if CONFIG_BOOT_RETRY_TIME or CONFIG_SHOW_ACTIVITY defined
Signed-off-by: Jens Scharsig <js_at_ng@scharsoft.de>
                while (!tstc()) {       /* while no incoming data */
                        if (retry_time >= 0 && get_ticks() > endtime)
                                return (-2);    /* timed out */
+                       WATCHDOG_RESET();
                }
 #endif
 
                while (!tstc()) {       /* while no incoming data */
                        if (retry_time >= 0 && get_ticks() > endtime)
                                return (-2);    /* timed out */
+                       WATCHDOG_RESET();
                }
 #endif
                WATCHDOG_RESET();               /* Trigger watchdog, if needed */
                while (!tstc()) {
                        extern void show_activity(int arg);
                        show_activity(0);
+                       WATCHDOG_RESET();
                }
 #endif
                c = getc();