rtl_bt: de-dupe identical config.bin files

A number of the rtl_bt files are identical according to sha256sum
so let's de-dupe them, and also remove a couple of entries in
the WHENCE file that are duplicates while we're at it.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>

WHENCE

@@ -4075,26 +4075,26 @@ Link: rtl_bt/rtl8821a_config.bin -> rtl8821c_config.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
+Link: rtl_bt/rtl8723d_config.bin -> rtl8821c_config.bin
 File: rtl_bt/rtl8821c_fw.bin
 File: rtl_bt/rtl8821c_config.bin
 File: rtl_bt/rtl8821cs_fw.bin
-File: rtl_bt/rtl8821cs_config.bin
+Link: rtl_bt/rtl8821cs_config.bin -> rtl8761b_config.bin
 File: rtl_bt/rtl8822cu_fw.bin
-File: rtl_bt/rtl8822cu_config.bin
+Link: rtl_bt/rtl8822cu_config.bin -> rtl8761bu_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
+Link: rtl_bt/rtl8852au_config.bin -> rtl8761bu_config.bin
 File: rtl_bt/rtl8852bu_fw.bin
-File: rtl_bt/rtl8852bu_config.bin
+Link: rtl_bt/rtl8852bu_config.bin -> rtl8761bu_config.bin
 File: rtl_bt/rtl8852cu_fw.bin
 File: rtl_bt/rtl8852cu_fw_v2.bin
-File: rtl_bt/rtl8852cu_config.bin
+Link: rtl_bt/rtl8852cu_config.bin -> rtl8761bu_config.bin
 File: rtl_bt/rtl8851bu_fw.bin
-File: rtl_bt/rtl8851bu_config.bin
+Link: rtl_bt/rtl8851bu_config.bin -> rtl8761bu_config.bin
 File: rtl_bt/rtl8852btu_fw.bin
-File: rtl_bt/rtl8852btu_config.bin
+Link: rtl_bt/rtl8852btu_config.bin -> rtl8761bu_config.bin
 
 Licence: Redistributable. See LICENCE.rtlwifi_firmware.txt for details.
 
@@ -4103,10 +4103,6 @@ From https://github.com/troy-tan/driver_store
 Files rtl_bt/rtl8822b_* came directly from Realtek. These files are
 updated on April 14, 2017.
 
-Found in vendor driver, 20200806_LINUX_BT_DRIVER_RTL8761B_COEX_v0202.zip
-File rtl_bt/rtl8761b_config.bin
-File rtl_bt/rtl8761bu_config.bin
-
 --------------------------------------------------------------------------
 
 Driver: btmtk_usb - Bluetooth USB driver