iwl3945: synchronize timestamp with uCode

In IBSS, TSF maintains local clock counters at each station. Network
Synchronization follows a completely distributed scheme where beacon frames
are generated. Each station maintain its own TSF timestamp, extracted from
beacon timestamps they recieved. Following patch synchronize this beacon timestamp
with uCode.

Signed-off-by: Abhijeet Kolekar <abhijeet.kolekar@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl3945-base.c

@@ -4305,6 +4305,7 @@ static int iwl3945_mac_beacon_update(struct ieee80211_hw *hw, struct sk_buff *sk
 {
 	struct iwl_priv *priv = hw->priv;
 	unsigned long flags;
+	__le64 timestamp;
 
 	IWL_DEBUG_MAC80211(priv, "enter\n");
 
@@ -4326,6 +4327,8 @@ static int iwl3945_mac_beacon_update(struct ieee80211_hw *hw, struct sk_buff *sk
 	priv->ibss_beacon = skb;
 
 	priv->assoc_id = 0;
+	timestamp = ((struct ieee80211_mgmt *)skb->data)->u.beacon.timestamp;
+	priv->timestamp = le64_to_cpu(timestamp);
 
 	IWL_DEBUG_MAC80211(priv, "leave\n");
 	spin_unlock_irqrestore(&priv->lock, flags);