r8169: add support for RTL8125D rev.b

Add support for RTL8125D rev.b. Its XID is 0x689. It is basically
based on the one with XID 0x688, but with different firmware file.

Signed-off-by: ChunHao Lin <hau@realtek.com>
[hkallweit1@gmail.com: rebased after adjusted version numbering]
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/75e5e9ec-d01f-43ac-b0f4-e7456baf18d1@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>