[llvm] [RISCV] Remove vmv.s.x and vmv.x.s lmul pseudo variants (PR #71501)

[Craig Topper via llvm-commits]

topperc wrote:

Do we still compile this with a single vsetvli after this change https://godbolt.org/z/bvGd46zWa

https://github.com/llvm/llvm-project/pull/71501