In the meantime, we use mainline Linux 6.18 by default:
‐ https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/arch/arm64/boot/dts/rockchip/rk3588-orangepi-5.dtsi#n76
In case, here is how to migrate from vendor Linux 6.1 to mainline Linux 6.18: Rock 5B switch to mainline kernel - #2 by MichaIng
Adjust the U-Boot package name accordingly.