ath9k: initialize hw prior to debugfs

debugfs uses the hardware for several debugfs files as such the
hardware must be initialized and available prior to its usage. The
same applies to when we free the hw structs -- free debufs file
entries prior to free'ing the hardware.

Reported-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath.h

@@ -23,6 +23,11 @@
 
 static const u8 ath_bcast_mac[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 
+enum ath_device_state {
+	ATH_HW_UNAVAILABLE,
+	ATH_HW_INITIALIZED,
+};
+
 struct reg_dmn_pair_mapping {
 	u16 regDmnEnum;
 	u16 reg_5ghz_ctl;
@@ -59,6 +64,7 @@ struct ath_common {
 	void *priv;
 	struct ieee80211_hw *hw;
 	int debug_mask;
+	enum ath_device_state state;
 
 	u16 cachelsz;
 	u16 curaid;