net: dsa: microchip: add support for common phylink mac link up

This patch add the support for common phylink mac link up for the ksz
series switch. The register address, bit position and values are
configured based on the chip id to the dev->info structure.

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>