mac80211: move fragment flag to info flag as dont-fragment

The purpose of this is two-fold:
 1) by moving it out of tx_data.flags, we can in
    another patch move the radiotap parsing so it
    no longer is in the hotpath
 2) if a device implements fragmentation but can
    optionally skip it, the radiotap request for
    not doing fragmentation may be honoured

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/net/mac80211.h

@@ -375,6 +375,9 @@ struct ieee80211_bss_conf {
  * @IEEE80211_TX_CTL_USE_MINRATE: This frame will be sent at lowest rate.
  *	This flag is used to send nullfunc frame at minimum rate when
  *	the nullfunc is used for connection monitoring purpose.
+ * @IEEE80211_TX_CTL_DONTFRAG: Don't fragment this packet even if it
+ *	would be fragmented by size (this is optional, only used for
+ *	monitor injection).
  *
  * Note: If you have to add new flags to the enumeration, then don't
  *	 forget to update %IEEE80211_TX_TEMPORARY_FLAGS when necessary.
@@ -408,6 +411,7 @@ enum mac80211_tx_control_flags {
 	IEEE80211_TX_CTL_NO_CCK_RATE		= BIT(27),
 	IEEE80211_TX_STATUS_EOSP		= BIT(28),
 	IEEE80211_TX_CTL_USE_MINRATE		= BIT(29),
+	IEEE80211_TX_CTL_DONTFRAG		= BIT(30),
 };
 
 #define IEEE80211_TX_CTL_STBC_SHIFT		23