net: sh_eth: fix the parameter for the ETHER of SH7757

If the driver didn't set this parameter on the ETHER, the CPU will
encounter the "data address error" exception.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>