wlan: Update weak zone RSSI threshold to firmware

Sometimes STA roams to new AP whose RSSI is poor but better
than current AP. For example if current AP RSSI is -85,
firmware may choose to roam to an AP whose RSSI is -83 and
connection may not go through.

To avoid this add an absolute RSSI param which will disallow
candidates whose RSSI is below this param.

Change-Id: I7309ae05e0f62f252f243b1402a0593a66d800a9
CRs-Fixed: 2052958
diff --git a/CORE/SME/inc/csrInternal.h b/CORE/SME/inc/csrInternal.h
index 3934fd9..3d1fff6 100644
--- a/CORE/SME/inc/csrInternal.h
+++ b/CORE/SME/inc/csrInternal.h
@@ -520,6 +520,7 @@
     tANI_U16       nNeighborResultsRefreshPeriod;
     tANI_U16       nEmptyScanRefreshPeriod;
     tANI_U8        nNeighborInitialForcedRoamTo5GhEnable;
+    tANI_U8        nWeakZoneRssiThresholdForRoam;
 }tCsrNeighborRoamConfig;
 #endif