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/Makefile b/drivers/net/wireless/iwlwifi/Makefile
index 4e378fa..e31a5cc 100644
--- a/drivers/net/wireless/iwlwifi/Makefile
+++ b/drivers/net/wireless/iwlwifi/Makefile
@@ -9,7 +9,7 @@
 
 # AGN
 obj-$(CONFIG_IWLAGN)	+= iwlagn.o
-iwlagn-objs		:= iwl-agn.o iwl-agn-rs.o iwl-agn-led.o
+iwlagn-objs		:= iwl-agn.o iwl-agn-rs.o iwl-agn-led.o iwl-agn-ict.o
 
 iwlagn-$(CONFIG_IWL4965) += iwl-4965.o
 iwlagn-$(CONFIG_IWL5000) += iwl-5000.o