Bluetooth: Add a new HCI_USE_DEBUG_KEYS flag

To pave the way for actively using debug keys for pairing this patch
adds a new HCI_USE_DEBUG_KEYS flag for the purpose. When the flag is set
we issue a HCI_Write_SSP_Debug mode whenever HCI_Write_SSP_Mode(0x01)
has been issued as well as before issuing a HCI_Write_SSP_Mode(0x00)
command.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index ffb489e..cc2e88d 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -125,6 +125,7 @@
 	HCI_PAIRABLE,
 	HCI_SERVICE_CACHE,
 	HCI_KEEP_DEBUG_KEYS,
+	HCI_USE_DEBUG_KEYS,
 	HCI_UNREGISTER,
 	HCI_USER_CHANNEL,