ath: Add a bus type field

This can be used to store the bus types ( AHB/PCI/USB ).

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/ahb.c b/drivers/net/wireless/ath/ath9k/ahb.c
index ca4994f..85fdd26 100644
--- a/drivers/net/wireless/ath/ath9k/ahb.c
+++ b/drivers/net/wireless/ath/ath9k/ahb.c
@@ -47,6 +47,7 @@
 }
 
 static struct ath_bus_ops ath_ahb_bus_ops  = {
+	.ath_bus_type = ATH_AHB,
 	.read_cachesize = ath_ahb_read_cachesize,
 	.eeprom_read = ath_ahb_eeprom_read,
 };