Note, that since version 2017.07 the sunxi targets needs the Python
libfdt library on the host. Therefore, additionally select the U-Boot
config option BR2_TARGET_UBOOT_NEEDS_PYLIBFDT.

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>