[NFC] Add extra RUN line to strict reduction tests

I have added RUN lines to both:

  Transforms/LoopVectorize/AArch64/strict-fadd.ll
  Transforms/LoopVectorize/AArch64/scalable-strict-fadd.ll

to show the default behaviour is to not vectorise when the following
flag is unset:

  -force-ordered-reductions