rtw89: extend role_maintain to support AP mode

Fill mac_id and self_role depends on the operation mode.

In AP mode, echo connected station has an unique mac_id, and each vif also
has one mac_id to represent itself.

The self_role is assigned to vif if the operation mode is decided, and
RTW89_SELF_ROLE_AP_CLIENT is assigned to the connected STA in AP mode,

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220207063900.43643-2-pkshih@realtek.com