Wi-Fi: set softap beacon DTIM count according to TSF timer

components/esp_wifi/include/esp_wifi_types.h

@@ -220,7 +220,7 @@ typedef struct {
     wifi_auth_mode_t authmode;  /**< Auth mode of ESP32 soft-AP. Do not support AUTH_WEP in soft-AP mode */
     uint8_t ssid_hidden;        /**< Broadcast SSID or not, default 0, broadcast the SSID */
     uint8_t max_connection;     /**< Max number of stations allowed to connect in, default 4, max 10 */
-    uint16_t beacon_interval;   /**< Beacon interval, 100 ~ 60000 ms, default 100 ms */
+    uint16_t beacon_interval;   /**< Beacon interval which should be multiples of 100. Unit: TU(time unit, 1 TU = 1024 us). Range: 100 ~ 60000. Default value: 100 */
 } wifi_ap_config_t;
 
 /** @brief STA configuration settings for the ESP32 */