Bluetooth: Replace L2CAP link mode with security level

Change the L2CAP internals to use the new security levels and remove
the link mode details.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 73e115b..29f720e 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -237,8 +237,9 @@
 	__u16		imtu;
 	__u16		omtu;
 	__u16		flush_to;
-
-	__u32		link_mode;
+	__u8            sec_level;
+	__u8		role_switch;
+	__u8            force_reliable;
 
 	__u8		conf_req[64];
 	__u8		conf_len;