net: phy: Update copyright info

For implementing this driver most of the inputs is
provided by Andrew Lunn.

Updating the driver with Andrew Copy right.

Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>