iwlwifi: code cleanup for generic defines

Some defines used by all agn devices, but the definitions were in
iwl-4965-hw.h, move those to iwl-agn-hw.h which is the better place for
those.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
index 257e4af..ad6cb1b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
@@ -404,7 +404,7 @@
 	if (ieee80211_is_probe_resp(fc))
 		data_retry_limit = 3;
 	else
-		data_retry_limit = IWL_DEFAULT_TX_RETRY;
+		data_retry_limit = IWLAGN_DEFAULT_TX_RETRY;
 	tx_cmd->data_retry_limit = data_retry_limit;
 
 	/* Set retry limit on RTS packets */