wlan: Add config parameter for PER based roam full scan

DUT should do a full scan if it is not able to find candidate
AP from the roam cache list. This full scan has to be done when
there is significant RSSI change which is configurable via ini.

Add changes for config paramer upon which full scan will be done.

CRs-Fixed: 1059278
Change-Id: Ia7b069f18560bebf3a593510bbd4babb293ea8b5
diff --git a/CORE/SME/inc/csrInternal.h b/CORE/SME/inc/csrInternal.h
index cb13a47..b987396 100644
--- a/CORE/SME/inc/csrInternal.h
+++ b/CORE/SME/inc/csrInternal.h
@@ -625,6 +625,7 @@
     tANI_BOOLEAN bFastRoamInConIniFeatureEnabled;
     v_BOOL_t     isPERRoamEnabled;
     v_BOOL_t     isPERRoamCCAEnabled;
+    v_S15_t      PERRoamFullScanThreshold;
     tANI_U32     rateUpThreshold;
     tANI_U32     rateDownThreshold;
     tANI_U32     waitPeriodForNextPERScan;