ath9k: fix compile error in ahb.c

drivers/net/wireless/ath9k/ahb.c: In function 'ath_ahb_probe':
drivers/net/wireless/ath9k/ahb.c:136: error: 'aphy' undeclared (first
use in this function)

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath9k/ahb.c b/drivers/net/wireless/ath9k/ahb.c
index bc562bd..00cc7bb 100644
--- a/drivers/net/wireless/ath9k/ahb.c
+++ b/drivers/net/wireless/ath9k/ahb.c
@@ -60,6 +60,7 @@
 static int ath_ahb_probe(struct platform_device *pdev)
 {
 	void __iomem *mem;
+	struct ath_wiphy *aphy;
 	struct ath_softc *sc;
 	struct ieee80211_hw *hw;
 	struct resource *res;