rtw88: move adaptivity mechanism to firmware

Current adaptivity mechanism is achieved in driver, by periodically
referencing the IGI value and then updating related registers.
But we find that this way may halt TX activity too long if huge
and temporary energy is detected frequently. So we move the mechanism
to firmware for immediately reacting this case to recover TX rapidly.

Signed-off-by: Chin-Yen Lee <timlee@realtek.com>
Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210830072014.12250-5-pkshih@realtek.com