rtw88: coex: 8723d: handle BT inquiry cases

Coex mechanism used to make BT have higher priority and more time to
transfer data when BT inquiry-page, which leads to poor WiFi performance.
Should take WiFi traffic into consideration. If the WiFi is having heavy
traffic, use another parameter to make sure WiFi has more chance to TX/RX,
while guarantee the priority of BT for inquiry. If the WiFi isn't busy
(connected or not), set proper parameter to fix originals.

Fixes: f5df1a8b ("rtw88: 8723d: Add 8723DE to Kconfig and Makefile")
Tested-by: You-Sheng Yang <vicamo.yang@canonical.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200529025009.2468-3-yhchuang@realtek.com