net: phy: broadcom: Add entry for 5395 switch PHYs

Add an entry for the builtin PHYs present in the Broadcom BCM5395 switch. This
allows us to retrieve the PHY statistics among other things.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Chris Healy <cphealy@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>