net/sh-ether: Fix build by removing ECSIPR_BRCRXIP and other

When support sh7734 of sh-ether, ECSIPR_BRCRXIP and other were removed.
Therefore SH7757 and SH7724 can not build. This revise this probelem.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>