net: pch_gbe: Remove power_{up,down}_phy HAL abstraction

For some reason the pch_gbe driver contains a struct pch_gbe_functions
with pointers used by a HAL abstraction layer, even though there is only
one implementation of each function.

This patch removes the power_up_phy & power_down_phy abstractions in
favor of calling pch_phy_power_up & pch_phy_power_down directly.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: David S. Miller <davem@davemloft.net>