b43: Beaconing fixes

These are some beaconing related fixes. Basically it prevents
the card from triggering the beacon IRQ over and over again.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h
index e478799..bf6b276 100644
--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -733,6 +733,7 @@
 	struct sk_buff *current_beacon;
 	bool beacon0_uploaded;
 	bool beacon1_uploaded;
+	struct work_struct beacon_update_trigger;
 
 	/* The current QOS parameters for the 4 queues.
 	 * This is protected by the irq_lock. */