configs/orangepi_zero_defconfig: refactoring, bump Linux and U-Boot versions

Changelog:
- Refactoring configs/orangepi_zero_defconfig.
- Linux: bump to version 5.15.16 (from 5.12.2).
- U-Boot: bump to version 2022.01 (from 2021.04).

Signed-off-by: Sergey Kuzminov <kuzminov.sergey81@gmail.com>
Reviewed-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Tested-by:  Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

configs/orangepi_zero_defconfig

@@ -1,49 +1,61 @@
+# Architecture
 BR2_arm=y
 BR2_cortex_a7=y
 BR2_ARM_FPU_VFPV4=y
-BR2_GLOBAL_PATCH_DIR="board/orangepi/orangepi-zero/patches"
-BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_MDEV=y
-BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_12=y
+
+# System
 BR2_TARGET_GENERIC_HOSTNAME="OrangePi_Zero"
 BR2_TARGET_GENERIC_ISSUE="Welcome to Buildroot for the Orange Pi Zero"
+BR2_GLOBAL_PATCH_DIR="board/orangepi/orangepi-zero/patches"
+BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_MDEV=y
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_15=y
 BR2_SYSTEM_DHCP="eth0"
+
+# Kernel
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.12.2"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.15.16"
 BR2_LINUX_KERNEL_DEFCONFIG="sunxi"
 BR2_LINUX_KERNEL_DTS_SUPPORT=y
 BR2_LINUX_KERNEL_INTREE_DTS_NAME="sun8i-h2-plus-orangepi-zero"
-BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="board/orangepi/orangepi-zero/linux-extras.config"
+BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="board/orangepi/orangepi-zero/linux-extras.fragment"
 BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
+
+# Filesystem
 BR2_TARGET_ROOTFS_EXT2=y
 BR2_TARGET_ROOTFS_EXT2_4=y
 # BR2_TARGET_ROOTFS_TAR is not set
+
+# Bootloader
 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="2022.01"
 BR2_TARGET_UBOOT_BOARD_DEFCONFIG="orangepi_zero"
 BR2_TARGET_UBOOT_NEEDS_DTC=y
 BR2_TARGET_UBOOT_NEEDS_PYTHON3=y
 BR2_TARGET_UBOOT_NEEDS_PYLIBFDT=y
 BR2_TARGET_UBOOT_SPL=y
 BR2_TARGET_UBOOT_SPL_NAME="u-boot-sunxi-with-spl.bin"
+
+# Required tools to create the SD image
 BR2_PACKAGE_HOST_UBOOT_TOOLS=y
 BR2_PACKAGE_HOST_UBOOT_TOOLS_BOOT_SCRIPT=y
 BR2_PACKAGE_HOST_UBOOT_TOOLS_BOOT_SCRIPT_SOURCE="board/orangepi/orangepi-zero/boot.cmd"
 BR2_PACKAGE_HOST_DOSFSTOOLS=y
 BR2_PACKAGE_HOST_GENIMAGE=y
 BR2_PACKAGE_HOST_MTOOLS=y
-BR2_PACKAGE_HOST_UBOOT_TOOLS=y
+
+# Image
 BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh"
 BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/orangepi/orangepi-zero/genimage.cfg"
 
-# wireless driver and firmware
+# Wireless driver and firmware
 BR2_PACKAGE_XR819_XRADIO=y
 BR2_PACKAGE_ARMBIAN_FIRMWARE=y
 BR2_PACKAGE_ARMBIAN_FIRMWARE_XR819=y
 
-# wireless support
+# Wireless support
 BR2_PACKAGE_IW=y
 BR2_PACKAGE_WIRELESS_TOOLS=y
 BR2_PACKAGE_WIRELESS_TOOLS_LIB=y
@@ -51,5 +63,5 @@ BR2_PACKAGE_WPA_SUPPLICANT=y
 BR2_PACKAGE_WPA_SUPPLICANT_NL80211=y
 BR2_PACKAGE_WPA_SUPPLICANT_CLI=y
 
-# spi flash support
+# Spi flash support
 BR2_PACKAGE_MTD=y