feat(esp_modem): example add esp32p4 usb support

1. support ec20 cat.4 module in example modem_console and pppos_client
2. support esp32p4 in example modem_console and pppos_client

components/esp_modem/include/esp_modem_c_api_types.h

@@ -52,6 +52,7 @@ typedef enum esp_modem_dce_device {
     ESP_MODEM_DCE_SIM7070,
     ESP_MODEM_DCE_SIM7000,
     ESP_MODEM_DCE_BG96,
+    ESP_MODEM_DCE_EC20,
     ESP_MODEM_DCE_SIM800,
     ESP_MODEM_DCE_CUSTOM
 } esp_modem_dce_device_t;