mac80211: add multi-rate retry support

This patch adjusts the rate control API to allow multi-rate retry
if supported by the driver. The ieee80211_hw struct specifies how
many alternate rate selections the driver supports.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rtl8180_dev.c b/drivers/net/wireless/rtl8180_dev.c
index abcd641..df7e78e 100644
--- a/drivers/net/wireless/rtl8180_dev.c
+++ b/drivers/net/wireless/rtl8180_dev.c
@@ -292,8 +292,8 @@
 	entry->plcp_len = cpu_to_le16(plcp_len);
 	entry->tx_buf = cpu_to_le32(mapping);
 	entry->frame_len = cpu_to_le32(skb->len);
-	entry->flags2 = info->control.alt_retry_rate_idx >= 0 ?
-		ieee80211_get_alt_retry_rate(dev, info)->bitrate << 4 : 0;
+	entry->flags2 = info->control.retries[0].rate_idx >= 0 ?
+		ieee80211_get_alt_retry_rate(dev, info, 0)->bitrate << 4 : 0;
 	entry->retry_limit = info->control.retry_limit;
 	entry->flags = cpu_to_le32(tx_flags);
 	__skb_queue_tail(&ring->queue, skb);
@@ -855,6 +855,7 @@
 	priv = dev->priv;
 	priv->pdev = pdev;
 
+	dev->max_altrates = 1;
 	SET_IEEE80211_DEV(dev, &pdev->dev);
 	pci_set_drvdata(pdev, dev);