net: sh_eth: Collect up EDMR_INIT_CNT to TIMEOUT_CNT

EDMR_INIT_CNT holds the check count of initialization.
Since there were more same values (1000), this collected as TIMEOUT_CNT.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>