Bluetooth: Add definitions for new link key types

With the introduction of Secure Connections, the list of link key types
got extended by P-256 versions of authenticated and unauthenticated
link keys.

To avoid any confusion the previous authenticated and unauthenticated
link key types got ammended with a P912 postfix. And the two new keys
have a P256 postfix now. Existing code using the previous definitions
has been adjusted.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

net/bluetooth/hci_conn.c

@@ -802,12 +802,12 @@ int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
 
 	/* An authenticated combination key has sufficient security for any
 	   security level. */
-	if (conn->key_type == HCI_LK_AUTH_COMBINATION)
+	if (conn->key_type == HCI_LK_AUTH_COMBINATION_P192)
 		goto encrypt;
 
 	/* An unauthenticated combination key has sufficient security for
 	   security level 1 and 2. */
-	if (conn->key_type == HCI_LK_UNAUTH_COMBINATION &&
+	if (conn->key_type == HCI_LK_UNAUTH_COMBINATION_P192 &&
 	    (sec_level == BT_SECURITY_MEDIUM || sec_level == BT_SECURITY_LOW))
 		goto encrypt;