MCInstrAnalysis: make GotPltSectionVA x86-32 specific

GotPltSectionVA is specific to x86-32 PIC PLT entries.
Let's remove the argument from the generic interface.

As a side effect of not requiring .got.plt, this simplification
addresses a subset of https://github.com/llvm/llvm-project/issues/62537
by enabling .plt dumping for some ld.bfd -z now linked x86-32/x86-64 images
without .got.plt