configs/licheepi_zero: U-Boot needs pylibfdt

Like all Allwinner platforms, building the licheepi_zero U-Boot
configuration requires pylibfdt.

Fixes:

  https://gitlab.com/buildroot.org/buildroot/-/jobs/378314331

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

configs/licheepi_zero_defconfig

@@ -39,6 +39,7 @@ BR2_TARGET_UBOOT_CUSTOM_VERSION=y
 BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2019.10"
 BR2_TARGET_UBOOT_BOARD_DEFCONFIG="LicheePi_Zero"
 BR2_TARGET_UBOOT_NEEDS_DTC=y
+BR2_TARGET_UBOOT_NEEDS_PYLIBFDT=y
 BR2_TARGET_UBOOT_FORMAT_CUSTOM=y
 BR2_TARGET_UBOOT_FORMAT_CUSTOM_NAME="u-boot-sunxi-with-spl.bin"
 BR2_TARGET_UBOOT_BOOT_SCRIPT=y