ath5k: beacon interval is in TU

the beacon interval is passed by mac80211 in TU already, so we can directly use
it without conversion. also update the comments about TU (1 TU is defined by
802.11 as 1024usec).

drivers/net/wireless/ath5k/ath5k.h:     Changes-licensed-under: ISC
drivers/net/wireless/ath5k/base.c:      Changes-licensed-under: 3-Clause-BSD
drivers/net/wireless/ath5k/base.h:      Changes-licensed-under: 3-Clause-BSD

Signed-off-by: Bruno Randolf <bruno@thinktube.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath5k/base.c b/drivers/net/wireless/ath5k/base.c
index 5ff115d..de59016 100644
--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -2554,7 +2554,7 @@
 {
 	struct ath5k_softc *sc = hw->priv;
 
-	sc->bintval = conf->beacon_int * 1000 / 1024;
+	sc->bintval = conf->beacon_int;
 	ath5k_setcurmode(sc, conf->phymode);
 
 	return ath5k_chan_set(sc, conf->chan);
@@ -2570,7 +2570,7 @@
 
 	/* Set to a reasonable value. Note that this will
 	 * be set to mac80211's value at ath5k_config(). */
-	sc->bintval = 1000 * 1000 / 1024;
+	sc->bintval = 1000;
 	mutex_lock(&sc->lock);
 	if (sc->vif != vif) {
 		ret = -EIO;