ARM: image: indent with tab instead of 4 spaces

Commit 6808ef9a ("move booti_setup to arch/arm/lig/image.c")
not only moved the code, but also replaced a tab with 4 spaces
to break the Linux coding style.

Restore tab indentation.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Bin Chen <bin.chen@linaro.org>