rtw89: update TMAC parameters

TMAC is short for TX MAC, and this patch is to configure FIFO thresholds.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220325060055.58482-16-pkshih@realtek.com