r8169: align RTL8125/RTL8126 PHY config with vendor driver

This aligns some parameters with vendor driver r8125/r8126 to avoid
compatibility issues. Note that for RTL8125B there's no functional
change, just the open-coded version of the function is replaced.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://patch.msgid.link/a8a9d896-fbe6-41f2-bf87-666567d3cdb3@gmail.com


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