configs/stm32mp157c_dk2: bump Linux and U-Boot versions

Needed to keep both stm32mp157c_dk1 and stm32mp157c_dk2
aligned.

Reported-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Pierre-Jean Texier <texier.pj2@gmail.com>
Reviewed-by: Sergey Matyukevich <geomatsi@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

configs/stm32mp157c_dk2_defconfig

@@ -1,11 +1,11 @@
 BR2_arm=y
 BR2_cortex_a7=y
-BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_12=y
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_13=y
 BR2_ROOTFS_OVERLAY="board/stmicroelectronics/stm32mp157c-dk2/overlay/"
 BR2_ROOTFS_POST_IMAGE_SCRIPT="board/stmicroelectronics/common/stm32mp157/post-image.sh"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.12.10"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.13"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/stmicroelectronics/stm32mp157c-dk2/linux.config"
 BR2_LINUX_KERNEL_DTS_SUPPORT=y
@@ -25,7 +25,7 @@ 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="2021.04"
+BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2021.07"
 BR2_TARGET_UBOOT_BOARD_DEFCONFIG="stm32mp15_trusted"
 # BR2_TARGET_UBOOT_FORMAT_BIN is not set
 BR2_TARGET_UBOOT_FORMAT_STM32=y