Revert "rtl_bt: Update RTL8852C BT USB firmware to 0x040D_7225"

Revert "rtl_bt: Update RTL8852C BT USB firmware to 0x040D_7225"

This reverts commit 55e7448533e774824cfb34a7eaeb9604608e1a4a.

Commit 55e7448533e7 replaced rtl_bt firmware with a v2 binary which
is not compatible with older kernels and introduced a regression.
Undo that and add the v2 binary later using a different filename.

Let the rtl8852cu_fw.bin file keep the firmware format v1 and stay
at version 0xD7B8_FABF.
Subsequent RTL8852C BT USB firmware format v2 updates will be
launched with rtl8852cu_fw_v2.bin

Suggested-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Hilda Wu <hildawu@realtek.com>
Reviewed-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Josh Boyer <jwboyer@kernel.org>