hci_le_start_enc
void hci_le_start_enc(struct hci_conn *conn, __le16 ediv, __le64 rand,
hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size);
hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size);
hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size);