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/b43/main.c b/drivers/net/wireless/b43/main.c
index 3bf74e2..14c44df 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -4588,6 +4588,7 @@
 		BIT(NL80211_IFTYPE_ADHOC);
 
 	hw->queues = b43_modparam_qos ? 4 : 1;
+	hw->max_altrates = 1;
 	SET_IEEE80211_DEV(hw, dev->dev);
 	if (is_valid_ether_addr(sprom->et1mac))
 		SET_IEEE80211_PERM_ADDR(hw, sprom->et1mac);