dpaa_eth: don't use fixed_phy_change_carrier

dpaa_eth: don't use fixed_phy_change_carrier

This effectively reverts 6e8b0ff1ba4c ("dpaa_eth: Add change_carrier()
for Fixed PHYs"). Usage of fixed_phy_change_carrier() requires that
fixed_phy_register() has been called before, directly or indirectly.
And that's not the case in this driver.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/7eb189b3-d5fd-4be6-8517-a66671a4e4e3@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>