ath6kl: add hif_type

In some rare cases core code needs to know what hif type is used. Add
a field to struct ath6kl to denote that. Hopefully this is just a
temporary solution.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
diff --git a/drivers/net/wireless/ath/ath6kl/sdio.c b/drivers/net/wireless/ath/ath6kl/sdio.c
index d61e39a..7ad57cd 100644
--- a/drivers/net/wireless/ath/ath6kl/sdio.c
+++ b/drivers/net/wireless/ath/ath6kl/sdio.c
@@ -1237,6 +1237,7 @@
 	}
 
 	ar_sdio->ar = ar;
+	ar->hif_type = ATH6KL_HIF_TYPE_SDIO;
 	ar->hif_priv = ar_sdio;
 	ar->hif_ops = &ath6kl_sdio_ops;
 	ar->bmi.max_data_size = 256;