iwlagn: move ICT code into separate file

All the ICT ISR code is iwlagn specific, and doesn't
need to be in iwlcore. So create a new iwl-agn.h
header file that will hold agn specific function
declarations etc., and move the ICT code into a new
iwl-agn-ict.c file that is linked into iwlagn. This
also gets rid of exporting those symbols.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-6000.c b/drivers/net/wireless/iwlwifi/iwl-6000.c
index c4844ad..4b7bc00 100644
--- a/drivers/net/wireless/iwlwifi/iwl-6000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-6000.c
@@ -42,6 +42,7 @@
 #include "iwl-core.h"
 #include "iwl-io.h"
 #include "iwl-sta.h"
+#include "iwl-agn.h"
 #include "iwl-helpers.h"
 #include "iwl-5000-hw.h"
 #include "iwl-6000-hw.h"