[LV] Simplify ARM/AArch64 interleaved access cost model tests (NFC)

This patch removes unneeded instructions from the existing ARM/AArch64
interleaved access cost model tests. I'll be adding a similar set of tests in a
follow-on patch to increase coverage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294336 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed