rtl_bt: Add firmware and configuration files for the Bluetooth parts of RTL8821C and RTL8723D

These devices are new models from Realtek. Updates to driver btrtl will
soon be submitted to the kernel.

These files were provided by the Realtek developer.
Signed-off-by: 陆朱伟 <alex_lu@realsil.com.cn>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Josh Boyer <jwboyer@kernel.org>

WHENCE

@@ -3001,6 +3001,10 @@ File: rtl_bt/rtl8812ae_fw.bin
 File: rtl_bt/rtl8821a_fw.bin
 File: rtl_bt/rtl8822b_fw.bin
 File: rtl_bt/rtl8822b_config.bin
+File: rtl_bt/rtl8723d_fw.bin
+File: rtl_bt/rtl8723d_config.bin
+File: rtl_bt/rtl8821c_fw.bin
+File: rtl_bt/rtl8821c_config.bin
 
 Licence: Redistributable. See LICENCE.rtlwifi_firmware.txt for details.
 
@@ -3008,6 +3012,7 @@ Found in vendor driver, linux_bt_usb_2.11.20140423_8723be.rar
 From https://github.com/troy-tan/driver_store
 Files rtl_bt/rtl8822b_* came directly from Realtek. These files are
 updated on April 14, 2017.
+Files rtl_bt/rtl8821c_* and rtl_bt/rtl8723d_* came directly from Realtek.
 
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