[2.0.x] Add optional menu item to toggle software endstops (#10389)

Marlin/src/lcd/language/language_en.h

@@ -55,6 +55,9 @@
 #ifndef MSG_LCD_ENDSTOPS
   #define MSG_LCD_ENDSTOPS                    _UxGT("Endstops") // Max length 8 characters
 #endif
+#ifndef MSG_LCD_SOFT_ENDSTOPS
+  #define MSG_LCD_SOFT_ENDSTOPS               _UxGT("Soft Endstops")
+#endif
 #ifndef MSG_MAIN
   #define MSG_MAIN                            _UxGT("Main")
 #endif