net: phy: micrel: add support for KSZ8795

This is adds support for the PHYs in the KSZ8795 5port managed switch.

It will allow to detect the link between the switch and the soc
and uses the same read_status functions as the KSZ8873MLL switch.

Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>