Bluetooth: Add more L2CAP convenience callbacks

In preparation for converting SMP to use l2cap_chan it's useful to add a
few more callback helpers so that smp.c won't need to define all of its
own.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 4a51e75..a72965f 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -838,18 +838,43 @@
 	return NULL;
 }
 
+static inline int l2cap_chan_no_recv(struct l2cap_chan *chan, struct sk_buff *skb)
+{
+	return -ENOSYS;
+}
+
+static inline struct sk_buff *l2cap_chan_no_alloc_skb(struct l2cap_chan *chan,
+						      unsigned long hdr_len,
+						      unsigned long len, int nb)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
 static inline void l2cap_chan_no_teardown(struct l2cap_chan *chan, int err)
 {
 }
 
+static inline void l2cap_chan_no_close(struct l2cap_chan *chan)
+{
+}
+
 static inline void l2cap_chan_no_ready(struct l2cap_chan *chan)
 {
 }
 
+static inline void l2cap_chan_no_state_change(struct l2cap_chan *chan,
+					      int state, int err)
+{
+}
+
 static inline void l2cap_chan_no_defer(struct l2cap_chan *chan)
 {
 }
 
+static inline void l2cap_chan_no_suspend(struct l2cap_chan *chan)
+{
+}
+
 static inline void l2cap_chan_no_resume(struct l2cap_chan *chan)
 {
 }