wlan: Fix race conditions while configuring mc/bc filter

multicast/broadcast filter is configured when the device goes into
suspend. Fix race conditions that can occur while configuring the filter.

Change-Id: I90aa40cf67b7335222adadc1aac821427100ab42
CRs-Fixed: 540698
diff --git a/CORE/HDD/inc/wlan_hdd_main.h b/CORE/HDD/inc/wlan_hdd_main.h
index dbca411..09cabf4 100644
--- a/CORE/HDD/inc/wlan_hdd_main.h
+++ b/CORE/HDD/inc/wlan_hdd_main.h
@@ -1040,6 +1040,8 @@
 
     v_U8_t sus_res_mcastbcast_filter;
 
+    v_BOOL_t sus_res_mcastbcast_filter_valid;
+
     /* debugfs entry */
     struct dentry *debugfs_phy;