rtw88: coex: Update rtl8822c COEX version to 22020720

Enable Wi-Fi/BT mailbox 0x45 handshake and Wi-Fi MIMO power save
mechanism for Bluetooth gaming controller.

BTCOEX Version: 22020720-2020
Desired_BT_Coex_Ver: 0x20
Desired_WL_FW_Ver: 9.9.11

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/20220215004855.4098-7-pkshih@realtek.com