ath9k: Fix bug in NF calibration

The number of chainmasks for AR9285 weren't being
setup when running NF calibration.
Signed-off-by: NSujith <Sujith.Manoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath9k/calib.c

@@ -620,7 +620,9 @@ void ath9k_hw_loadnf(struct ath_hal *ah, struct ath9k_channel *chan)
 	};
 	u8 chainmask;
 
-	if (AR_SREV_9280(ah))
+	if (AR_SREV_9285(ah))
+		chainmask = 0x9;
+	else if (AR_SREV_9280(ah))
 		chainmask = 0x1B;
 	else
 		chainmask = 0x3F;