https://bugs.freedesktop.org/show_bug.cgi?id=103576
--- Comment #1 from Christian König deathsimple@vodafone.de --- IIRC the ASIC is identical, just configuration parameter like amount of video memory and clocks are different.
As you can see on the lspci output even the PCI-IDs are the same. So why should amdgpu differentiate between the two?