trusty: keymaster: Implement abort

keymaster_error_t TrustyKeymasterDevice::abort(keymaster_operation_handle_t operation_handle) {

    ALOGD("Device received abort");

    return KM_ERROR_OK;

    if (error_ != KM_ERROR_OK) {

        return error_;

    }

    AbortOperationRequest request;

    request.op_handle = operation_handle;

    AbortOperationResponse response;

    return Send(KM_ABORT_OPERATION, request, &response);

}

hw_device_t* TrustyKeymasterDevice::hw_device() {