rtlwifi: btcoex: 23b 2ant: add btc8723b2ant_limited_rx to reduce agg size

For wifi and bt coexistence, if the aggregation size of wifi is too
large, the transmission time of the aggregated packet could be too long
and the bt packets might "cut off" the wifi packet. We need to reduce
the aggregation size to improve wifi performance.

Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Pkshih <pkshih@realtek.com>
Cc: Birming Chiu <birming@realtek.com>
Cc: Shaofu <shaofu@realtek.com>
Cc: Steven Ting <steventing@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>