caif: Use rcu_read_lock in CAIF mux layer.

Replace spin_lock with rcu_read_lock when accessing lists to layers
and cache. While packets are in flight rcu_read_lock should not be held,
instead ref-counters are used in combination with RCU.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/caif/cffrml.h b/include/net/caif/cffrml.h
index 3f14d2e..4f126d7 100644
--- a/include/net/caif/cffrml.h
+++ b/include/net/caif/cffrml.h
@@ -12,5 +12,7 @@
 struct cflayer *cffrml_create(u16 phyid, bool DoFCS);
 void cffrml_set_uplayer(struct cflayer *this, struct cflayer *up);
 void cffrml_set_dnlayer(struct cflayer *this, struct cflayer *dn);
+void cffrml_put(struct cflayer *layr);
+void cffrml_hold(struct cflayer *layr);
 
 #endif /* CFFRML_H_ */