wlan: Enable roaming on DFS channel

Added a  configuration item to control the
roaming on DFS channels.
'gAllowDFSChannelRoam = 1' will enable the roaming
on DFS channels.

Change-Id: Id5b253d22469446b32b8949b8c3869b5d2397eb5
CRs-fixed: 628110
diff --git a/CORE/SME/inc/csrInternal.h b/CORE/SME/inc/csrInternal.h
index dda5b73..35960bd 100644
--- a/CORE/SME/inc/csrInternal.h
+++ b/CORE/SME/inc/csrInternal.h
@@ -661,6 +661,7 @@
     tANI_U8 isAmsduSupportInAMPDU;
     tANI_U8 nSelect5GHzMargin;
     tANI_U8 isCoalesingInIBSSAllowed;
+    tANI_U8 allowDFSChannelRoam;
 }tCsrConfig;
 
 typedef struct tagCsrChannelPowerInfo