esp_wifi: modify WiFi buffer number type from uint8_t to uint16_t
esp_wifi: modify WiFi buffer number type from uint8_t to uint16_t

Modify WiFi receiving buffer number type from uint8_t to uint16_t to support
configuring more than 255 buffers.

espressif/esp-idf,espressif/esp-idf,espressif/esp-idf,espressif/esp-idf