net: dsa: b53: provide own phylink MAC operations

Convert b53 to provide its own phylink MAC operations, thus avoiding the
shim layer in DSA's port.c

Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20240423183339.1368511-9-florian.fainelli@broadcom.com


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