qcacld-3.0: Add stub functions for beacon_stats sysfs

Build failure is seen with CONFIG_SYSFS=y and
CONFIG_FEATURE_BECN_STATS=n.

Fix is to add stub declarations for
hdd_sysfs_create_bcn_reception_interface and
hdd_sysfs_destroy_bcn_reception_interface.

Change-Id: I1b1522305ea40d524e9a354211a2e38d4b4cb9d5
CRs-Fixed: 3508273

core/hdd/src/wlan_hdd_sysfs.c

@@ -779,8 +779,19 @@ static void hdd_sysfs_destroy_bcn_reception_interface(struct hdd_adapter
 {
 	device_remove_file(&adapter->dev->dev, &dev_attr_beacon_stats);
 }
+#else /* !WLAN_FEATURE_BEACON_RECEPTION_STATS */
+static inline int
+hdd_sysfs_create_bcn_reception_interface(struct hdd_adapter *adapter)
+{
+	return 0;
+}
 
-#endif
+static inline void
+hdd_sysfs_destroy_bcn_reception_interface(struct hdd_adapter *adapter)
+{
+}
+
+#endif /* WLAN_FEATURE_BEACON_RECEPTION_STATS */
 
 static void
 hdd_sysfs_create_sta_adapter_root_obj(struct hdd_adapter *adapter)