configs/stm32mp157c_odyssey: specify uboot custom version

According to buildroot requirements set custom uboot
version instead of relying on the newest one.

Signed-off-by: Bartosz Bilas <b.bilas@grinn-global.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

configs/stm32mp157c_odyssey_defconfig

@@ -22,6 +22,9 @@ BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_VARIABLES="STM32MP_SDMMC=1 AARCH32_SP
 BR2_TARGET_ARM_TRUSTED_FIRMWARE_IMAGES="*.stm32"
 BR2_TARGET_ARM_TRUSTED_FIRMWARE_NEEDS_DTC=y
 BR2_TARGET_UBOOT=y
+BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
+BR2_TARGET_UBOOT_CUSTOM_VERSION=y
+BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2021.10"
 BR2_TARGET_UBOOT_BOARD_DEFCONFIG="stm32mp15_trusted"
 BR2_TARGET_UBOOT_NEEDS_DTC=y
 # BR2_TARGET_UBOOT_FORMAT_BIN is not set