rt2800: zero registers of unused TX rings

This is needed if we take over after drivers which use those.

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Reviewed-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2800pci.c b/drivers/net/wireless/rt2x00/rt2800pci.c
index 4366c23..f9f36cf 100644
--- a/drivers/net/wireless/rt2x00/rt2800pci.c
+++ b/drivers/net/wireless/rt2x00/rt2800pci.c
@@ -393,6 +393,16 @@
 	rt2x00pci_register_write(rt2x00dev, TX_CTX_IDX3, 0);
 	rt2x00pci_register_write(rt2x00dev, TX_DTX_IDX3, 0);
 
+	rt2x00pci_register_write(rt2x00dev, TX_BASE_PTR4, 0);
+	rt2x00pci_register_write(rt2x00dev, TX_MAX_CNT4, 0);
+	rt2x00pci_register_write(rt2x00dev, TX_CTX_IDX4, 0);
+	rt2x00pci_register_write(rt2x00dev, TX_DTX_IDX4, 0);
+
+	rt2x00pci_register_write(rt2x00dev, TX_BASE_PTR5, 0);
+	rt2x00pci_register_write(rt2x00dev, TX_MAX_CNT5, 0);
+	rt2x00pci_register_write(rt2x00dev, TX_CTX_IDX5, 0);
+	rt2x00pci_register_write(rt2x00dev, TX_DTX_IDX5, 0);
+
 	entry_priv = rt2x00dev->rx->entries[0].priv_data;
 	rt2x00pci_register_write(rt2x00dev, RX_BASE_PTR, entry_priv->desc_dma);
 	rt2x00pci_register_write(rt2x00dev, RX_MAX_CNT,