net: dsa: mt7530: provide own phylink MAC operations

Convert mt753x to provide its own phylink MAC operations, thus avoiding
the shim layer in DSA's port.c

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Link: https://lore.kernel.org/r/E1rvIco-006bQu-Fq@rmk-PC.armlinux.org.uk


Signed-off-by: Paolo Abeni <pabeni@redhat.com>