[X86][Atom] Fix vector integer multiplication resource/throughputs

Match whats documented in the Intel AOM (and Agner/instlatx64 agree) - vector integer multiplies are pipelined - all Port0, throughput = 2 @ 128bits, 1 @ 64bits.

Noticed while checking reduction costs - now that we can use in-order models in llvm-mca, the atom model is the "worst case scenario" we have in x86.