drivers/lcd: remove nxsig_notification when signal support is disabled

When all signals are disabled, nxsig_notification is not available and
should not be invoked. Remove the call to avoid build and runtime issues
in no-signal configurations.

Signed-off-by: Chengdong Wang <wangchengdong@lixiang.com>

drivers/lcd/ft80x.c

@@ -258,6 +258,11 @@ static int ft80x_fade(FAR struct ft80x_dev_s *priv,
 static void ft80x_notify(FAR struct ft80x_dev_s *priv,
                          enum ft80x_notify_e id, int value)
 {
+#ifdef CONFIG_DISABLE_ALL_SIGNALS
+    UNUSED(priv);
+    UNUSED(id);
+    UNUSED(value);
+#else
   FAR struct ft80x_eventinfo_s *info = &priv->notify[id];
 
   /* Are notifications enabled for this event? */
@@ -271,6 +276,7 @@ static void ft80x_notify(FAR struct ft80x_dev_s *priv,
       info->event.sigev_value.sival_int = value;
       nxsig_notification(info->pid, &info->event, SI_QUEUE, &info->work);
     }
+#endif
 }
 
 /****************************************************************************
@@ -997,6 +1003,7 @@ static int ft80x_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
        *   Returns:      None
        */
 
+#ifndef CONFIG_DISABLE_ALL_SIGNALS
       case FT80X_IOC_EVENTNOTIFY:
         {
           FAR struct ft80x_notify_s *notify =
@@ -1059,7 +1066,7 @@ static int ft80x_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
             }
         }
         break;
-
+#endif
        /* FT80X_IOC_FADE:
         *   Description:  Change the backlight intensity with a controllable
         *                 fade.

drivers/lcd/ft80x.h

@@ -188,7 +188,9 @@ struct ft80x_dev_s
 
   /* Event notification support */
 
+#ifndef CONFIG_DISABLE_ALL_SIGNALS
   struct ft80x_eventinfo_s notify[FT80X_INT_NEVENTS];
+#endif
 };
 
 /****************************************************************************