net: phy: Add DP83825I to the DP83822 driver

Add the DP83825I ethernet PHY to the DP83822 driver.
These devices share the same WoL register bits and addresses.

The phy_driver init was made into a macro as there may be future
devices appended to this driver that will share the register space.

http://www.ti.com/lit/gpn/dp83825i



Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>