fix(wifi): fix arp and dns affect signaling test issue

1. fix arp and dns affects signaling test issue
2. improve ap chnnel parameter documentation
3. fix set country change ap channel issue
4. fix beacon timeout too long issue
5. only unicast frames count as keep-alive

components/esp_rom/esp32c2/ld/esp32c2.rom.eco4.ld

@@ -81,7 +81,7 @@ ieee80211_ampdu_reorder = 0x40001fb0;
 ieee80211_encap_esfbuf = 0x40001fb8;
 ieee80211_output_process = 0x40001fc4;
 /* sta_input = 0x40001fcc; */
-ieee80211_classify = 0x40001fe0;
+/*ieee80211_classify = 0x40001fe0;*/
 ieee80211_crypto_decap = 0x40001ff8;
 //ieee80211_ccmp_decrypt = 0x4000200c;
 //ieee80211_ccmp_encrypt = 0x40002010;

components/esp_wifi/include/esp_wifi_types_generic.h

@@ -516,7 +516,7 @@ typedef struct {
     uint8_t ssid[32];                         /**< SSID of soft-AP. If ssid_len field is 0, this must be a Null terminated string. Otherwise, length is set according to ssid_len. */
     uint8_t password[64];                     /**< Password of soft-AP. */
     uint8_t ssid_len;                         /**< Optional length of SSID field. */
-    uint8_t channel;                          /**< Channel of soft-AP */
+    uint8_t channel;                          /**< Channel of soft-AP. Set to 0 for auto selection (min channel: typically 1 for 2.4G, 36 for 5G). Other invalid values return ESP_ERR_INVALID_ARG. */
     wifi_auth_mode_t authmode;                /**< Auth mode of soft-AP. Do not support AUTH_WEP, AUTH_WAPI_PSK and AUTH_OWE in soft-AP mode. When the auth mode is set to WPA2_PSK, WPA2_WPA3_PSK or WPA3_PSK, the pairwise cipher will be overwritten with WIFI_CIPHER_TYPE_CCMP by default, unless explicitly set.  */
     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 */