[U-Boot] [U-Boot, RESEND, 2/2] rockchip: make_fit_atf: make python3 compatible

[Philipp Tomsich]

> Make script python3 compatible. No functional changes intended.
> 
> Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab at suse.com>
> Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> ---
>  arch/arm/mach-rockchip/make_fit_atf.py | 89 +++++++++++++++++-----------------
>  1 file changed, 45 insertions(+), 44 deletions(-)
> 

Applied to u-boot-rockchip, thanks!