orange-pi-5-max: init

[vlinkz]

Description of changes

Added orange-pi-5-max

Things done

• Tested the changes in your own NixOS Configuration
• Tested the changes end-to-end by using your fork of nixos-hardware and
  importing it via <nixos-hardware> or Flake input

[JRodez]

Hi,
What features are covered by this PR ?

[vlinkz]

Hi,
What features are covered by this PR ?

Pretty much everything supported by the base Ubuntu Image:

• u-boot
• configurable uart
• graphics drivers
• audio
• wifi/bluetooth

[vlinkz]

Ok so this was a bit painful, but given kernel 6.15 has upstream support for more features I was able to make the same featureset as the vendor kernel (probably something missing but what I mentioned above) work with the mainline kernel. Still depending on a custom bcmdhd driver for wifi support, but hopefully mainline gets support for the ap6611s wifi card in brcmfmac driver in 6.16 or soon after. Couple of notes:

• Mesa 25.1.x adds support for VK_KHR_sampler_ycbcr_conversion in panfrost driver for mali g610, until it is available I set GDK_VULKAN_DISABLE=ycbcr as otherwise gtk apps fail to launch.
• Bluetooth support with btbcm works given the supplied device tree overlay is applied, I suspect these changes will land in kernel 6.16.