* @brief Connect a peripheral signal which tagged as output attribute with a RTC(LP) GPIO
*
* @note There's no limitation on the number of RTC(LP) GPIOs that a signal can connect with
*
* @param gpio_num GPIO number
* @param signal_idx LP peripheral signal index (tagged as input attribute), especially, `SIG_LP_GPIO_OUT_IDX` means disconnect RTC(LP) GPIO and other peripherals. Only the RTC GPIO driver can control the output level
* @param out_inv Whether to signal to be inverted or not