mediatek: add support for CMCC A10

This board is also as known as SuperElectron ZN-M5 and ZN-M8. However,
for ZN-M5 and ZN-M8, there's another version uses ZX279128 as CPU
chip, which is unsupported.
You can check it in "高级设置" > "系统日志" > "内核日志" page from webUI.

Hardware specification:
  SoC: MediaTek MT7981B 2x A53
  Flash: 128 MB SPI-NAND
  RAM: 256MB
  Ethernet: 4x 10/100/1000 Mbps
  Switch: MediaTek MT7531AE
  WiFi: MediaTek MT7976C
  Button: Reset, WPS
  Power: DC 12V 1A

Stock layout flash instructions:
Login into webUI and upload sysupgrade firmware in "系统管理" > "升级固件" page.
Remember to unselect "保留配置" ("Keep configurations") first before doing that.

OpenWrt U-Boot layout flash instructions:
1. Flash stock layout firmware first.
2. Connect to the device via SSH, and backup everything,
   especially 'Factory' partition.
3. Unlock MTD partitions:
   opkg update && opkg install kmod-mtd-rw
   insmod mtd-rw i_want_a_brick=1
4. Write new BL2 and FIP:
   mtd write openwrt-mediatek-filogic-cmcc_a10-ubootmod-preloader.bin BL2
   mtd write openwrt-mediatek-filogic-cmcc_a10-ubootmod-bl31-uboot.fip FIP
5. Set static IP on your PC:
   IP 192.168.1.254/24, GW 192.168.1.1
6. Serve OpenWrt initramfs image using TFTP server.
7. Cut off the power and re-engage, wait for TFTP recovery to complete.
8. After OpenWrt has booted, perform sysupgrade.

Signed-off-by: Tianling Shen <cnsztl@immortalwrt.org>
Link: https://github.com/openwrt/openwrt/pull/18121
(cherry picked from commit 96c6608346)
[sync uboot defconfigs with 24.10 branch, change apk to opkg]
Signed-off-by: Tianling Shen <cnsztl@immortalwrt.org>
Link: https://github.com/openwrt/openwrt/pull/18218
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

target/linux/mediatek/image/filogic.mk

@@ -500,6 +500,61 @@ define Device/cetron_ct3003
 endef
 TARGET_DEVICES += cetron_ct3003
 
+define Device/cmcc_a10-stock
+  DEVICE_VENDOR := CMCC
+  DEVICE_MODEL := A10 (stock layout)
+  DEVICE_ALT0_VENDOR := SuperElectron
+  DEVICE_ALT0_MODEL := ZN-M5 (stock layout)
+  DEVICE_ALT1_VENDOR := SuperElectron
+  DEVICE_ALT1_MODEL := ZN-M8 (stock layout)
+  DEVICE_DTS := mt7981b-cmcc-a10-stock
+  DEVICE_DTS_DIR := ../dts
+  SUPPORTED_DEVICES += mediatek,mt7981-spim-snand-rfb
+  DEVICE_PACKAGES := kmod-mt7915e kmod-mt7981-firmware mt7981-wo-firmware
+  UBINIZE_OPTS := -E 5
+  BLOCKSIZE := 128k
+  PAGESIZE := 2048
+  IMAGE_SIZE := 65536k
+  KERNEL_IN_UBI := 1
+  IMAGES += factory.bin
+  IMAGE/factory.bin := append-ubi | check-size $$$$(IMAGE_SIZE)
+  IMAGE/sysupgrade.bin := sysupgrade-tar | append-metadata
+  KERNEL = kernel-bin | lzma | \
+	fit lzma $$(KDIR)/image-$$(firstword $$(DEVICE_DTS)).dtb
+  KERNEL_INITRAMFS = kernel-bin | lzma | \
+	fit lzma $$(KDIR)/image-$$(firstword $$(DEVICE_DTS)).dtb with-initrd
+endef
+TARGET_DEVICES += cmcc_a10-stock
+
+define Device/cmcc_a10-ubootmod
+  DEVICE_VENDOR := CMCC
+  DEVICE_MODEL := A10 (OpenWrt U-Boot layout)
+  DEVICE_ALT0_VENDOR := SuperElectron
+  DEVICE_ALT0_MODEL := ZN-M5 (OpenWrt U-Boot layout)
+  DEVICE_ALT1_VENDOR := SuperElectron
+  DEVICE_ALT1_MODEL := ZN-M8 (OpenWrt U-Boot layout)
+  DEVICE_DTS := mt7981b-cmcc-a10-ubootmod
+  DEVICE_DTS_DIR := ../dts
+  SUPPORTED_DEVICES += cmcc,a10
+  DEVICE_PACKAGES := kmod-mt7915e kmod-mt7981-firmware mt7981-wo-firmware
+  UBINIZE_OPTS := -E 5
+  BLOCKSIZE := 128k
+  PAGESIZE := 2048
+  KERNEL_IN_UBI := 1
+  UBOOTENV_IN_UBI := 1
+  IMAGES := sysupgrade.itb
+  KERNEL_INITRAMFS_SUFFIX := -recovery.itb
+  KERNEL := kernel-bin | gzip
+  KERNEL_INITRAMFS := kernel-bin | lzma | \
+	fit lzma $$(KDIR)/image-$$(firstword $$(DEVICE_DTS)).dtb with-initrd | pad-to 64k
+  IMAGE/sysupgrade.itb := append-kernel | \
+	fit gzip $$(KDIR)/image-$$(firstword $$(DEVICE_DTS)).dtb external-static-with-rootfs | append-metadata
+  ARTIFACTS := preloader.bin bl31-uboot.fip
+  ARTIFACT/preloader.bin := mt7981-bl2 spim-nand-ddr3
+  ARTIFACT/bl31-uboot.fip := mt7981-bl31-uboot cmcc_a10
+endef
+TARGET_DEVICES += cmcc_a10-ubootmod
+
 define Device/cmcc_rax3000m
   DEVICE_VENDOR := CMCC
   DEVICE_MODEL := RAX3000M