rtl_bt: Add firmware and config files for RTL8852A BT USB chip

The firmware and config files are for RTL8852A BT controller with USB interface.

Version: 0xd99a_7644
Signed-off-by: Max Chou <max.chou@realtek.com>
Signed-off-by: Josh Boyer <jwboyer@kernel.org>

WHENCE

@@ -3656,6 +3656,8 @@ File: rtl_bt/rtl8822cu_fw.bin
 File: rtl_bt/rtl8822cu_config.bin
 File: rtl_bt/rtl8822cs_fw.bin
 File: rtl_bt/rtl8822cs_config.bin
+File: rtl_bt/rtl8852au_fw.bin
+File: rtl_bt/rtl8852au_config.bin
 
 Licence: Redistributable. See LICENCE.rtlwifi_firmware.txt for details.