mediatek: add ubootmod layout for Cudy WBR3000UAX v1

This allows us to use the full size of nand,
which extends ubi size from 64Mb to 122.25Mb.

If you are at factory firmware, please refer
to [PR](openwrt#21141)
to boot into OpenWrt first.

1. Log in to the device and backup all the partitions,
especially unique `Factory` and `bdata` partitions
from System -> Backup / Flash Firmware -> Save mtdblock contents.
2. Install kmod-mtd-rw to unlock mtd partitions for writing:
```bash
apk update && apk add kmod-mtd-rw && insmod mtd-rw i_want_a_brick=1
```
3. Write new OpenWrt (U-Boot Layout) `BL2` and `FIP`:
```bash
mtd write openwrt-mediatek-filogic-cudy_wbr3000uax-v1-ubootmod-preloader.bin BL2
mtd write openwrt-mediatek-filogic-cudy_wbr3000uax-v1-ubootmod-bl31-uboot.fip FIP
```
4. Set static IP on your PC: `192.168.1.254`, gateway `192.168.1.1`
5. Serve openwrt-mediatek-filogic-cudy_wbr3000uax-v1-ubootmod-initramfs-recovery.itb
using TFTP server.
6. Connect Router LAN with PC LAN.
7. Cut off the power and re-engage, wait for TFTP recovery to complete.
8. After OpenWrt initramfs recovery has booted,
clean `/dev/mtd5` ubi partition to utilize maximum of free space:
```bash
ubidetach -p /dev/mtd5; ubiformat /dev/mtd5 -y; ubiattach -p /dev/mtd5
```
4. Perform sysupgrade.

Tested-by: 4pda users
Signed-off-by: Fil Dunsky <filipp.dunsky@gmail.com>

Author: fildunsky

package/boot/arm-trusted-firmware-mediatek/Makefile

@@ -262,8 +262,8 @@ define Trusted-Firmware-A/mt7981-spim-nand-ubi-ddr4
   USE_UBI:=1
 endef
 
-define Trusted-Firmware-A/mt7981-cudy-tr3000-v1
-  NAME:=Cudy TR3000 v1 (SPI-NAND via SPIM, DDR3)
+define Trusted-Firmware-A/mt7981-cudy-ddr3
+  NAME:=Cudy (SPI-NAND via SPIM, DDR3)
   BOOT_DEVICE:=spim-nand
   BUILD_SUBTARGET:=filogic
   PLAT:=mt7981
@@ -664,7 +664,7 @@ TFA_TARGETS:= \
 	mt7981-emmc-ddr4 \
 	mt7981-sdmmc-ddr4 \
 	mt7981-spim-nand-ddr4 \
-	mt7981-cudy-tr3000-v1 \
+	mt7981-cudy-ddr3 \
 	mt7986-ram-ddr3 \
 	mt7986-emmc-ddr3 \
 	mt7986-nor-ddr3 \

package/boot/uboot-mediatek/Makefile

@@ -311,7 +311,18 @@ define U-Boot/mt7981_cudy_tr3000-v1
   UBOOT_IMAGE:=u-boot.fip
   BL2_BOOTDEV:=cudy-tr3000-v1
   BL2_SOC:=mt7981
-  DEPENDS:=+trusted-firmware-a-mt7981-cudy-tr3000-v1
+  DEPENDS:=+trusted-firmware-a-mt7981-cudy-ddr3
+endef
+
+define U-Boot/mt7981_cudy_wbr3000uax-v1
+  NAME:=Cudy WBR3000UAX v1
+  BUILD_SUBTARGET:=filogic
+  BUILD_DEVICES:=cudy_wbr3000uax-v1-ubootmod
+  UBOOT_CONFIG:=mt7981_cudy_wbr3000uax-v1
+  UBOOT_IMAGE:=u-boot.fip
+  BL2_BOOTDEV:=cudy-wbr3000uax-v1
+  BL2_SOC:=mt7981
+  DEPENDS:=+trusted-firmware-a-mt7981-cudy-ddr3
 endef
 
 define U-Boot/mt7981_glinet_gl-mt2500
@@ -1091,6 +1102,7 @@ UBOOT_TARGETS := \
 	mt7981_cmcc_rax3000m-nand-ddr4 \
 	mt7981_comfast_cf-wr632ax \
 	mt7981_cudy_tr3000-v1 \
+	mt7981_cudy_wbr3000uax-v1 \
 	mt7981_gatonetworks_gdsp \
 	mt7981_glinet_gl-mt2500 \
 	mt7981_glinet_gl-x3000 \