[Bluetooth] Fix L2CAP configuration parameter handling

The L2CAP configuration parameter handling was missing the support
for rejecting unknown options. The capability to reject unknown
options is mandatory since the Bluetooth 1.2 specification. This
patch implements its and also simplifies the parameter parsing.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 8242a0e..87df4e8 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -129,8 +129,10 @@
 	__u8       data[0];
 } __attribute__ ((packed));
 
-#define L2CAP_CONF_SUCCESS	0x00
-#define L2CAP_CONF_UNACCEPT	0x01
+#define L2CAP_CONF_SUCCESS	0x0000
+#define L2CAP_CONF_UNACCEPT	0x0001
+#define L2CAP_CONF_REJECT	0x0002
+#define L2CAP_CONF_UNKNOWN	0x0003
 
 struct l2cap_conf_opt {
 	__u8       type;
@@ -215,6 +217,8 @@
 
 	__u32		link_mode;
 
+	__u8		conf_req[64];
+	__u8		conf_len;
 	__u8		conf_state;
 	__u8		conf_retry;
 	__u16		conf_mtu;