gpio_etm_event_bind_gpio() function

- ESP_OK: Set the GPIO for ETM event successfully - ESP_ERR_INVALID_ARG: Set the GPIO for ETM event failed because of invalid argument, e.g. GPIO is not input capable, ETM event is not of GPIO type - ESP_FAIL: Set the GPIO for ETM event failed because of other reasons

Calling this function multiple times with different GPIO number can override the previous setting immediately. Only GPIO ETM object can call this function