rtlwifi: 8822be has to report vht capability to mac80211

8822be is 2x2 11ac wifi chip, so report VHT capability to mac80211.

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>