rtw89: coex: Move _set_policy to chip_ops

Due to the difference of Wi-Fi firmware supported feature, RTL8852C
need to defined more policy to enable the features.
(Ex: DBCC, Wi-Fi multi-role, TDMA instant and so on)

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/20220725023509.43114-8-pkshih@realtek.com