[llvm] [RISCV][llvm-mca] Vector Unit Stride Loads and stores use EEW and EMU… (PR #69409)

[Wang Pengcheng via llvm-commits]

https://github.com/wangpc-pp approved this pull request.

LGTM with nit.
(Besides, what about strided/indexed load/store? Do we need to do the same thing?)

https://github.com/llvm/llvm-project/pull/69409