The clocks for the Rockchip Ethernet controller need to be enabled much

The clocks for the Rockchip Ethernet controller need to be enabled much
earlier.  So far we haven't noticed this, as we had the assumption that
all clocks are enabled anyway.  On the NanoPi R4S this does not seem to
be the case, so we need to bring the clock enable code closer to the
other bringup code.

ok kettenis@