rtw88: coex: add action for coexistence in hardware initial

The original setting misses some necessary configuration.
Make coexistence slot align to beacon and check the connection situation
to know if we need to extend WLAN slot or not.

Signed-off-by: Ching-Te Ku <ku920601@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/20201126021059.11981-9-pkshih@realtek.com