iwlagn: transport layer receives struct iwl_trans*

It still holds a pointer to iwl_priv. But hopefully this will disappear at some point.
Also add the multiple inclusion protection to iwl-trans.h that was forgotten.
Move iwl-trans structures to iwl-trans.h

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-sta.c b/drivers/net/wireless/iwlwifi/iwl-sta.c
index 65386e5..58dba0a 100644
--- a/drivers/net/wireless/iwlwifi/iwl-sta.c
+++ b/drivers/net/wireless/iwlwifi/iwl-sta.c
@@ -168,7 +168,7 @@
 	}
 
 	cmd.len[0] = iwlagn_build_addsta_hcmd(sta, data);
-	ret = trans_send_cmd(priv, &cmd);
+	ret = trans_send_cmd(&priv->trans, &cmd);
 
 	if (ret || (flags & CMD_ASYNC))
 		return ret;
@@ -424,7 +424,7 @@
 
 	cmd.flags |= CMD_WANT_SKB;
 
-	ret = trans_send_cmd(priv, &cmd);
+	ret = trans_send_cmd(&priv->trans, &cmd);
 
 	if (ret)
 		return ret;
@@ -793,7 +793,7 @@
 		return -EINVAL;
 
 	if (is_lq_table_valid(priv, ctx, lq))
-		ret = trans_send_cmd(priv, &cmd);
+		ret = trans_send_cmd(&priv->trans, &cmd);
 	else
 		ret = -EINVAL;