wifi: rtw89: coex: refactor _chk_btc_report() to extend more features

wifi: rtw89: coex: refactor _chk_btc_report() to extend more features

Change the checking logic to switch case. Make the code more readable.
There are more feature including to common code, in order to commit the
following version of the features, switch case will make the logic more
clearly. This patch did not change logic.

Signed-off-by: Ching-Te Ku <ku920601@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20221217141745.43291-7-pkshih@realtek.com