Rename dtb_override to dtb_autodetect

[rhythm16]

This ambiguity has caused confusion, for example in https://discourse.ubuntu.com/t/faq-ubuntu-25-04-25-10-on-snapdragon-x-elite/61016/112 , dtb_override=true was suggested when false was actually required to load a custom device tree.

[askiiart]

Might wanna add an "alias" that reverses it for compatibility with preexisting scripts and such

[rhythm16]

@askiiart thanks for your suggestion!

[tobhe]

I think this generally makes sense and I agree the name is not perfect, but I am not convinced autodetect=false is entirely correct either.

This setting only changes one particular case: If there is already a DTB registered in EFI (usually from grub or dtbloader) then stubble will only replace it with an embedded one based on the compatible string it if override=true., so override=false means stubble won't override the previous dtb. "autodetect" sounds like it would also disable the hwid based lookup which it doesn't.

Also: If we deprecate the old one I'd say there is no need to document the old one, the only reason to keep it around is to not cause unexpected behavior changes.

[rhythm16]

@tobhe Thanks for the info, sorry for posting before fully understanding the behavior, I see your point after reading the code.
What about dtb_source=stubble/efi or prefer_efi_dtb=true/false?