rtlwifi: enable mac80211 fast-tx support

Enable the mac80211 fast-tx feature, since our driver already support
hw_flags required by fast-tx and is able to let mac80211 stack to transmit
packet through fast-xmit path.

Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtlwifi/base.c

@@ -397,6 +397,7 @@ static void _rtl_init_mac80211(struct ieee80211_hw *hw)
 	ieee80211_hw_set(hw, MFP_CAPABLE);
 	ieee80211_hw_set(hw, REPORTS_TX_ACK_STATUS);
 	ieee80211_hw_set(hw, SUPPORTS_AMSDU_IN_AMPDU);
+	ieee80211_hw_set(hw, SUPPORT_FAST_XMIT);
 
 	/* swlps or hwlps has been set in diff chip in init_sw_vars */
 	if (rtlpriv->psc.swctrl_lps) {