wlan: Add configuration option for bad RSSI in PER based roaming

In PER based roaming candidate selection, candidates are
discarded if their RSSI are too low which is considered
as bad RSSI.

Add changes to remove constant value for bad RSSI and add
configuration parameter based on ini.

CRs-Fixed: 1094330
Change-Id: Ia0a442a27c06cec82de8112b7c11fb30a0e14493
diff --git a/CORE/SME/inc/csrInternal.h b/CORE/SME/inc/csrInternal.h
index 67492e3..a780af6 100644
--- a/CORE/SME/inc/csrInternal.h
+++ b/CORE/SME/inc/csrInternal.h
@@ -627,6 +627,7 @@
     v_BOOL_t     isPERRoamEnabled;
     v_BOOL_t     isPERRoamCCAEnabled;
     v_S15_t      PERRoamFullScanThreshold;
+    v_S15_t      PERMinRssiThresholdForRoam;
     tANI_U32     rateUpThreshold;
     tANI_U32     rateDownThreshold;
     tANI_U32     waitPeriodForNextPERScan;