[openwrt/openwrt] uboot-rockchip: add Radxa E20C support

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/9aca1216d142d68e719e2161cd32cca6d9af1dca

commit 9aca1216d142d68e719e2161cd32cca6d9af1dca
Author: Tianling Shen <cnsztl at immortalwrt.org>
AuthorDate: Sat Oct 11 17:04:08 2025 +0800

    uboot-rockchip: add Radxa E20C support
    
    Add support for the Radxa E20C board.
    
    Signed-off-by: Tianling Shen <cnsztl at immortalwrt.org>
    Link: https://github.com/openwrt/openwrt/pull/20375
    Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
 package/boot/uboot-rockchip/Makefile | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/package/boot/uboot-rockchip/Makefile b/package/boot/uboot-rockchip/Makefile
index addeeca309..78cfe52064 100644
--- a/package/boot/uboot-rockchip/Makefile
+++ b/package/boot/uboot-rockchip/Makefile
@@ -165,6 +165,23 @@ define U-Boot/rockpro64-rk3399
 endef
 
 
+# RK3528 boards
+
+define U-Boot/rk3528/Default
+  BUILD_SUBTARGET:=armv8
+  DEPENDS:=+PACKAGE_u-boot-$(1):trusted-firmware-a-rk3528
+  ATF:=rk3528_bl31_v1.20.elf
+  TPL:=rk3528_ddr_1056MHz_v1.11.bin
+endef
+
+define U-Boot/radxa-e20c-rk3528
+  $(U-Boot/rk3528/Default)
+  NAME:=E20C
+  BUILD_DEVICES:= \
+    radxa_e20c
+endef
+
+
 # RK3566 boards
 
 define U-Boot/rk3566/Default
@@ -395,6 +412,7 @@ UBOOT_TARGETS := \
   rock64-rk3328 \
   rock-pi-e-rk3328 \
   rock-pi-e-v3-rk3328 \
+  radxa-e20c-rk3528 \
   nanopi-r3s-rk3566 \
   radxa-cm3-io-rk3566 \
   radxa-zero-3-rk3566 \