esp8266/modesp: Remove unused constants: STA_MODE, etc.

WiFi mode selection happens on the level of individual interfaces.

esp8266/modesp.c

@@ -384,13 +384,6 @@ STATIC const mp_map_elem_t esp_module_globals_table[] = {
         MP_OBJ_NEW_SMALL_INT(LIGHT_SLEEP_T) },
     { MP_OBJ_NEW_QSTR(MP_QSTR_SLEEP_MODEM),
         MP_OBJ_NEW_SMALL_INT(MODEM_SLEEP_T) },
-
-    { MP_OBJ_NEW_QSTR(MP_QSTR_STA_MODE),
-        MP_OBJ_NEW_SMALL_INT(STATION_MODE)},
-    { MP_OBJ_NEW_QSTR(MP_QSTR_AP_MODE),
-        MP_OBJ_NEW_SMALL_INT(SOFTAP_MODE)},
-    { MP_OBJ_NEW_QSTR(MP_QSTR_STA_AP_MODE),
-        MP_OBJ_NEW_SMALL_INT(STATIONAP_MODE)},
 #endif
 };