iwlagn: introduce iwl-shared.h

It will hold declaration of functions and forward declaration of struct that
are used by several layers.
This will allow modules not to include iwl_priv. iwl_bus and iwl_trans are
still visible to all.

All the layers share the module parameters, move the struct to iwl-shared.h.
Also add all module parameters to iwl_mod_params instead of having them as
global static. This includes

* debug_level
* ant_coupling
* bt_ch_announce
* wanted_ucode_alternative

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index 8e31400..8b3a089 100644
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -40,6 +40,7 @@
 #include "iwl-helpers.h"
 #include "iwl-agn-calib.h"
 #include "iwl-agn.h"
+#include "iwl-shared.h"
 
 
 /******************************************************************************