Bluetooth: Add constants for LTK key types

The LTK key types available right now are unauthenticated and
authenticated ones. Provide two simple constants for it.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 232c078..352d3d7 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -346,6 +346,10 @@
 #define HCI_SMP_LTK			0x82
 #define HCI_SMP_LTK_SLAVE		0x83
 
+/* Long Term Key types */
+#define HCI_LTK_UNAUTH			0x00
+#define HCI_LTK_AUTH			0x01
+
 /* ---- HCI Error Codes ---- */
 #define HCI_ERROR_AUTH_FAILURE		0x05
 #define HCI_ERROR_CONNECTION_TIMEOUT	0x08