configs/imx8mn_bsh_smm_s2_pro_defconfig: bump U-Boot version to 2023.04

Bump U-Boot to version 2023.04.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>

configs/imx8mn_bsh_smm_s2_pro_defconfig

@@ -28,7 +28,7 @@ BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_VARIABLES="IMX_BOOT_UART_BASE=0x30a60
 BR2_TARGET_UBOOT=y
 BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
 BR2_TARGET_UBOOT_CUSTOM_VERSION=y
-BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2022.07"
+BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2023.04"
 BR2_TARGET_UBOOT_BOARD_DEFCONFIG="imx8mn_bsh_smm_s2pro"
 BR2_TARGET_UBOOT_NEEDS_DTC=y
 BR2_TARGET_UBOOT_NEEDS_PYLIBFDT=y