Bluetooth: Enable LE encryption events only when supported

The support for LE encryption is optional. When encryption is not
supported then also do not enable the encryption related events.

This moves the event mask setting to the third initialization
stage to ensure that the LE features are available.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 7f754a2..2fee852 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -329,6 +329,7 @@
 #define LMP_HOST_SC		0x08
 
 /* LE features */
+#define HCI_LE_ENCRYPTION		0x01
 #define HCI_LE_CONN_PARAM_REQ_PROC	0x02
 #define HCI_LE_PING			0x10