net: dsa: mt7530: convert to phylink managed EEE

Convert mt7530 to use phylink managed EEE. When enabling EEE, we set
both PMCR_FORCE_EEE1G and PMCR_FORCE_EEE100 irrespective of the speed,
and clear them both when disabling.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1thR9q-003vXI-Cp@rmk-PC.armlinux.org.uk


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