net: xscale: Drop unused PHY number

For some cargoculted reason on incomplete cleanup, we have a
PHY number which refers to nothing and gives confusing messages
about PHY 0 on all ports.

Print the name of the actual PHY device instead.

Reported-by: Howard Harte <hharte@magicandroidapps.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20231028-ixp4xx-eth-id-v1-1-57be486d7f0f@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>