Wi-Fi: remove wifi_fast_scan_threshold_t which is not suitable in name

components/esp_wifi/include/esp_wifi_types.h

@@ -181,9 +181,7 @@ typedef enum {
 typedef struct {
     int8_t              rssi;             /**< The minimum rssi to accept in the fast scan mode */
     wifi_auth_mode_t    authmode;         /**< The weakest authmode to accept in the fast scan mode */
-}wifi_fast_scan_threshold_t;
-
-typedef wifi_fast_scan_threshold_t wifi_scan_threshold_t;    /**< wifi_fast_scan_threshold_t only used in fast scan mode once, now it enabled in all channel scan, the wifi_fast_scan_threshold_t will be remove in version 4.0 */
+}wifi_scan_threshold_t;
 
 typedef enum {
     WIFI_PS_NONE,        /**< No power save */