ot::Spinel::RadioSpinel::GetMultipanActiveInterface() method

OT_ERROR_NONE Successfully got the property. OT_ERROR_RESPONSE_TIMEOUT Failed due to no response received from the transceiver. OT_ERROR_NOT_IMPLEMENTED Failed due to lack of the support in radio OT_ERROR_INVALID_COMMAND Platform supports all interfaces simultaneously. (i.e. no active/inactive interface concept in the platform level)