sh: ecovec: Change macro from BOARD_LATE_INIT to CONFIG_BOARD_LATE_INIT

When calling board_late_init, we need to define CONFIG_BOARD_LATE_INIT.
The latest ecovec config defines BOARD_LATE_INIT, board_late_init is not called.

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