[ELF] Pass `Relocation` to relaxGot and relaxTls{GdToIe,GdToLe,LdToLe,IeToLe}

These functions call relocateOne(). This patch is a prerequisite for
making relocateOne() aware of `Symbol` (D73254).

Reviewed By: grimar, nickdesaulniers

Differential Revision: https://reviews.llvm.org/D73250