dm: eth: Do not print misleading "Net Initialization Skipped"

With driver model, board_eth_init() or cpu_eth_init() is not a must.
Thus we don't need print a misleading "Net Initialization Skipped".

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>