jme: PHY Power control for new chip

After main chip rev 5, the hardware support more power saving
control registers.
Some Non-Linux drivers might turn off the phy power with new
interfaces, this patch makes it possible for Linux to turn it
on again.

Signed-off-by: Guo-Fu Tseng <cooldavid@cooldavid.org>
Signed-off-by: David S. Miller <davem@davemloft.net>