net: sh_eth: add cache handling

Some CPU needs cache handling. So this patch add the config of
CONFIG_SH_ETHER_CACHE_WRITEBACK, and it calls wback function.

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