sh: Fix building ecovec board

Build error was with board/renesas/ecovec/lowlevel_init.S
include/version.h: Assembler messages:
include/version.h:41: Error: unknown opcode
lowlevel_init.S:48: Error: unknown opcode
lowlevel_init.S:51: Error: unknown opcode
etc

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>