r8169: Add support for another RTL8168FP

According to the vendor driver, the new chip with XID 0x54b is
essentially the same as the one with XID 0x54a, but it doesn't need the
firmware.

So add support accordingly.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/20210202044813.1304266-1-kai.heng.feng@canonical.com


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