crt: Remove support for providing __CTOR_LIST__ for LLD 7 and older

This reverts commit ccda8b5229e428a6fa7036140778b23d11b554e8 and
removes the code for providing __CTOR_LIST__ here.

This was only needed for LLD 7 and older, while LLD 8 got support for
providing __CTOR_LIST__ by the linker, just as GNU ld does.

This gets rid of a brittle configure check and simplifies the code.

Signed-off-by: Martin Storsjö <martin@martin.st>