ath9k_hw: add AR9271 srev and device ID to allow hw to support ar9271

This allows for hw support to be enabled for ar9271.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index 773f5c4..f782c1a 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -33,13 +33,18 @@
 #include "../debug.h"
 
 #define ATHEROS_VENDOR_ID	0x168c
+
 #define AR5416_DEVID_PCI	0x0023
 #define AR5416_DEVID_PCIE	0x0024
 #define AR9160_DEVID_PCI	0x0027
 #define AR9280_DEVID_PCI	0x0029
 #define AR9280_DEVID_PCIE	0x002a
 #define AR9285_DEVID_PCIE	0x002b
+
 #define AR5416_AR9100_DEVID	0x000b
+
+#define AR9271_USB             0x9271
+
 #define	AR_SUBVENDOR_ID_NOG	0x0e11
 #define AR_SUBVENDOR_ID_NEW_A	0x7065
 #define AR5416_MAGIC		0x19641014