ath9k: port to cfg80211 rfkill

This ports the ath9k rfkill code to the new API offered by
cfg80211 and thus removes a lot of useless stuff.

("With this series a kernel panic, which is a regression, during module
unload disappears." -- Vasanthakumar Thiagarajan <vasanth@atheros.com>

Other patches in the series:

  ath9k: Add helper to get ath9k specific current channel
  ath9k: Make sure we have current channel in ah_curchan before rf
    disable/enable

-- JWL)

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis Rodriguez <mcgrof@gmail.com>
Tested-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ath9k.h

@@ -21,7 +21,6 @@
 #include <linux/device.h>
 #include <net/mac80211.h>
 #include <linux/leds.h>
-#include <linux/rfkill.h>
 
 #include "hw.h"
 #include "rc.h"
@@ -460,12 +459,6 @@ struct ath_led {
 	bool registered;
 };
 
-struct ath_rfkill {
-	struct rfkill *rfkill;
-	struct rfkill_ops ops;
-	char rfkill_name[32];
-};
-
 /********************/
 /* Main driver core */
 /********************/
@@ -505,7 +498,6 @@ struct ath_rfkill {
 #define SC_OP_PROTECT_ENABLE    BIT(6)
 #define SC_OP_RXFLUSH           BIT(7)
 #define SC_OP_LED_ASSOCIATED    BIT(8)
-#define SC_OP_RFKILL_REGISTERED BIT(9)
 #define SC_OP_WAIT_FOR_BEACON   BIT(12)
 #define SC_OP_LED_ON            BIT(13)
 #define SC_OP_SCANNING          BIT(14)
@@ -591,7 +583,6 @@ struct ath_softc {
 
 	int beacon_interval;
 
-	struct ath_rfkill rf_kill;
 	struct ath_ani ani;
 	struct ath9k_node_stats nodestats;
 #ifdef CONFIG_ATH9K_DEBUG