Rockchip: add initial support for RK356x

[Kwiboo]

This PR introduces initial support for Rockchip RK356x devices.

U-Boot 2023.07, scheduled for 03 July 2023, will be the first version with decent support for RK356x/RK3588.
The PR currently include and depends on #7365 and will be kept in draft state until u-boot package has been updated to 2023.07.

Main focus of this PR is:

• Adding initial RK3568 device support to the build system
• Update rkbin to latest version and add support for using ROCKCHIP_TPL when building U-Boot
• Boot RK356x devices using mainline U-Boot 2023.07

There are two variants of the SoC supported using the same device, RK3566 and RK3568, they are very similar but unfortunately require unique ddr init blobs.
A new soc value is defined for the added devices in scripts/uboot_helper, this value is used when building a bootable u-boot for the targeted device.

PR will be updated with related u-boot and minimal linux patches until U-Boot 2023.07 has been released.

Future PRs will focus on improving Linux display and media stack.

[MarkusTeufelberger]

I have a https://wiki.friendlyelec.com/wiki/index.php/NanoPi_R5C here that eventually is planned to run LibreELEC, if there is anything I can do to help/test please just comment here. Support for the device itself has ended up in Linux fairly recently (torvalds/linux@0562003), but at least it is already there. :-)

[Kwiboo]

@MarkusTeufelberger thanks, I have imported the r5c/r5s device tree into my local u-boot repo and will push patches and build images that can be tested in next few days. Still some rk356x u-boot patches to finalize and submit upstream before that.

[diederikdehaas]

I have a Pine64 Quartz64 Model A and B and if there's an image to download, I'd happily test it.

[zhangn1985]

I tested U-boot part, success build, flash, boot.

[zhangn1985]

is there any effort on rkvdec-v2 which used on RK3568

[MarkusTeufelberger]

u-boot is already at 2024.04 in this repo, is there still something missing to go forward with RK356x support?

[Kwiboo]

@MarkusTeufelberger not that I know, will try to update re-test this PR later this weekend.

Both mainline U-Boot and Linux kernel should be in a good enough state for most 1080p usage last time I checked.