add mangopi m28k board (#6121)

* add mangopi m28k board

config/boards/mangopi-m28k.csc

@@ -0,0 +1,19 @@
+# Rockchip RK3528 quad core 1-8GB SoC GBe eMMC PCIE Wifi Bt
+BOARD_NAME="Mangopi M28K"
+BOARDFAMILY="rk35xx"
+BOOTCONFIG="hinlink_rk3528_defconfig"
+BOARD_MAINTAINER="sputnik2019"
+KERNEL_TARGET="legacy"
+FULL_DESKTOP="yes"
+BOOT_LOGO="desktop"
+BOOT_FDT_FILE="rockchip/rk3528-mangopi-m28k.dtb"
+BOOT_SCENARIO="spl-blobs"
+WIREGUARD="no"
+IMAGE_PARTITION_TABLE="gpt"
+BOOTFS_TYPE="ext4"
+# Override family config for this board; let's avoid conditionals in family config.
+function post_family_config__hinlink-h28k_use_vendor_uboot() {
+	BOOTSOURCE='https://github.com/rockchip-linux/u-boot.git'
+	BOOTBRANCH='commit:32640b0ada9344f91e7a407576568782907161cd'
+	BOOTPATCHDIR="legacy/board_hinlink-h28k"
+}