rtw88: 8821ce: add support for device ID 0xb821

New device ID 0xb821 found on TP-Link T2E
Tested it with c821 driver. 2.4GHz and 5GHz works.

PCI id:
05:00.0 Network controller: Realtek Semiconductor Co., Ltd. Device b821
        Subsystem: Realtek Semiconductor Co., Ltd. Device b821

Signed-off-by: Jimmy Hon <honyuenkwun@gmail.com>
Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220407075123.420696-2-honyuenkwun@gmail.com