Add smartconfig capability to micropython for esp8266 and esp32

Add the following to modesp.c
{ MP_ROM_QSTR(MP_QSTR_smartconfig), MP_ROM_PTR(&mp_module_esp_smartconfig) },

Create smartconfig python wrapper. An old example is at https://github.com/mianos/micropython/blob/master/esp8266/mod_esp_smartconfig.c