caif: Add reference counting to service layer

Changes:
o Added functions cfsrvl_get and cfsrvl_put.
o Added support release_client to use by socket and net device.
o Increase reference counting for in-flight packets from cfmuxl

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/caif/cfsrvl.c b/net/caif/cfsrvl.c
index d470c51..aff31f3 100644
--- a/net/caif/cfsrvl.c
+++ b/net/caif/cfsrvl.c
@@ -158,6 +158,13 @@
 	service->layer.ctrlcmd = cfservl_ctrlcmd;
 	service->layer.modemcmd = cfservl_modemcmd;
 	service->dev_info = *dev_info;
+	kref_init(&service->ref);
+}
+
+void cfsrvl_release(struct kref *kref)
+{
+	struct cfsrvl *service = container_of(kref, struct cfsrvl, ref);
+	kfree(service);
 }
 
 bool cfsrvl_ready(struct cfsrvl *service, int *err)