Making them easier to use when including "limine" has a submodule.
Also renamed stivale2_hdr_tag_framebuffer to stivale2_header_tag_framebuffer.
This make it more consistant with other declaration in stivale2.
When trying to boot skift using limine I was still getting an invalid address for the stivale struct.
Pushing an additional 0 where the return address should have been fixed the issue.