rtw89: configure mac port HIQ registers

HIQ is short for high queue that is used to send broadcast/multicast
packets right after TBTT in AP mode. Two registers, DTIM and window size,
are configured accordingly.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220107034239.22002-10-pkshih@realtek.com