net: phy: dp83848: add dp83822 PHY support

This PHY has a compatible register set with DP83848x so
add support for it.

Acked-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>