mac80211: add flags for STBC (Space-Time Block Coding)

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 1252ba1..97b2eae 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -876,6 +876,7 @@
 #define IEEE80211_HT_CAP_SGI_40			0x0040
 #define IEEE80211_HT_CAP_TX_STBC		0x0080
 #define IEEE80211_HT_CAP_RX_STBC		0x0300
+#define		IEEE80211_HT_CAP_RX_STBC_SHIFT	8
 #define IEEE80211_HT_CAP_DELAY_BA		0x0400
 #define IEEE80211_HT_CAP_MAX_AMSDU		0x0800
 #define IEEE80211_HT_CAP_DSSSCCK40		0x1000