Add ROCK 5T support to upstream U-Boot

[martinholovsky]

Problem

Upstream U-Boot currently has support for several ROCK 5 series boards:

• ROCK 5A (rock5a-rk3588s_defconfig)
• ROCK 5B (rock5b-rk3588_defconfig)
• ROCK 5C (rock-5c-rk3588s_defconfig)
• ROCK 5 ITX (rock-5-itx-rk3588_defconfig)

However, ROCK 5T is missing from upstream U-Boot, despite being an officially released board.

Impact

This creates issues for community projects that rely on upstream U-Boot:

• Projects like sbc-rockchip (Talos Linux for SBCs) need upstream U-Boot support
• Users must work around the missing support by using configs from similar boards
• ROCK 5T is the only ROCK 5 series board without upstream support

Request

Could Radxa please:

1. Submit patches to upstream U-Boot to add ROCK 5T support (defconfig, device tree, board files), or
2. Provide technical documentation/guidance to help the community submit patches

Since ROCK 5T is similar to ROCK 5B (both use RK3588), adding support should be relatively straightforward.

Context

• ROCK 5T uses RK3588 SoC
• Linux kernel 6.17+ already includes DTB support for ROCK 5T
• Other ROCK 5 boards already have upstream U-Boot support
• Related: Mainline U-Boot Support for RK3588/RK3588S #14 (Mainline U-Boot Support for RK3588/RK3588S)

Thank you for considering this request!