configs/amarula_vyasa_rk3288: u-boot 2021.10 needs python3

Uboot 2021.10 needs python3 so enable it.

Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/1723729667

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

configs/amarula_vyasa_rk3288_defconfig

@@ -13,6 +13,7 @@ BR2_TARGET_UBOOT_CUSTOM_VERSION=y
 BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2021.10"
 BR2_TARGET_UBOOT_BOARD_DEFCONFIG="vyasa-rk3288"
 BR2_TARGET_UBOOT_NEEDS_DTC=y
+BR2_TARGET_UBOOT_NEEDS_PYTHON3=y
 BR2_TARGET_UBOOT_NEEDS_PYLIBFDT=y
 BR2_TARGET_UBOOT_NEEDS_OPENSSL=y
 BR2_TARGET_UBOOT_FORMAT_DTB_IMG=y