bauth: Add enumerate function

Change-Id: I452a651b2a1b11d3619ecde50f448812bf032b66
diff --git a/fingerprint/bauth/fingerprint.c b/fingerprint/bauth/fingerprint.c
index 5145de6..c2ee914 100644
--- a/fingerprint/bauth/fingerprint.c
+++ b/fingerprint/bauth/fingerprint.c
@@ -163,6 +163,11 @@
     return bauth_handle->ss_set_notify_callback(hal_notify_convert);
 }
 
+static int enumerate(struct fingerprint_device *dev __unused)
+{
+    return -1;
+}
+
 static int fingerprint_open(const hw_module_t* module, const char *id, hw_device_t** device)
 {
     int ret;
@@ -198,6 +203,7 @@
     dev->set_active_group = fingerprint_set_active_group;
     dev->authenticate = fingerprint_authenticate;
     dev->set_notify = set_notify_callback;
+    dev->enumerate = enumerate;
     dev->notify = NULL;
 
     *device = (hw_device_t*) dev;