Remove unused plane properties

[ajoneil]

libliftoff is now responsible for setting plane properties, so almost all these properties are not used directly.

The remaining three are still in use, as libliftoff matches layers to planes but does not allow direct reading of properties.

This also includes #1164, as that uncalled function references these properties directly causing compiler errors.

[misyltoad]

I was interested in doing a non-liftoff path for Deck given it seemed to take a bunch of time and AMDGPU is a universal plane architecture on newer DCN, so it provides no benefit from what I can tell.

In general, the dead code probably exists for some reason, like your previous MR.

[emersion]

Why not improve libliftoff/amdgpu instead?

[misyltoad]

It would be cool to improve liftoff so it wasn't spamming strcmp for everything, etc, but I think it makes sense to have another path for modern AMD DCN.

We'd still keep that path around for other vendors.

[emersion]

That sounds like a step back in terms of pushing for fully generic user-space…

[ajoneil]

In general, the dead code probably exists for some reason, like your previous MR.

The easiest way for me to extract this information out of your head is to put up a PR, which is why you'll often see me open small PRs - that way I can get early feedback before going too far in the wrong direction, and it's no stress if you find them unsuitable to be merged. :)

Once the missing finish_drm call is reinstated then these properties are again used so this isn't actually dead code, closing this PR!