mac80211: add ieee80211_vif param to tsf functions

TSF can be kept per vif.
Add ieee80211_vif param to set/get/reset_tsf, and move
the debugfs entries to the per-vif directory.

Update all the drivers that implement these callbacks.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c
index 0baeb89..6f51e39 100644
--- a/drivers/net/wireless/rt2x00/rt73usb.c
+++ b/drivers/net/wireless/rt2x00/rt73usb.c
@@ -2279,7 +2279,7 @@
 	return 0;
 }
 
-static u64 rt73usb_get_tsf(struct ieee80211_hw *hw)
+static u64 rt73usb_get_tsf(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 {
 	struct rt2x00_dev *rt2x00dev = hw->priv;
 	u64 tsf;