rt2x00: Centralize setting of extra TX headroom requested by rt2x00.

Set the value of extra_tx_headroom in a central place, rather than in each
of the drivers. This is preparatory for taking alignment space into account
in the TX headroom requested by rt2x00.

Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c
index 4cb9afe..687e17d 100644
--- a/drivers/net/wireless/rt2x00/rt61pci.c
+++ b/drivers/net/wireless/rt2x00/rt61pci.c
@@ -2546,7 +2546,6 @@
 	    IEEE80211_HW_SIGNAL_DBM |
 	    IEEE80211_HW_SUPPORTS_PS |
 	    IEEE80211_HW_PS_NULLFUNC_STACK;
-	rt2x00dev->hw->extra_tx_headroom = 0;
 
 	SET_IEEE80211_DEV(rt2x00dev->hw, rt2x00dev->dev);
 	SET_IEEE80211_PERM_ADDR(rt2x00dev->hw,
@@ -2794,6 +2793,7 @@
 	.eeprom_size		= EEPROM_SIZE,
 	.rf_size		= RF_SIZE,
 	.tx_queues		= NUM_TX_QUEUES,
+	.extra_tx_headroom	= 0,
 	.rx			= &rt61pci_queue_rx,
 	.tx			= &rt61pci_queue_tx,
 	.bcn			= &rt61pci_queue_bcn,