[AArch64][SME] Fix bug on SMELd1St1 (#118109)
Patch[1] has update intrinsic interface for ld1/st1, while based on
ARM's document, "If the intrinsic also has a vnum argument, the ZA slice
number is calculated by adding vnum to slice.". But the "vnum" did not
work for our realization now, this patch fix this point.
[1]https://github.com/llvm/llvm-project/commit/ee31ba0dd923c3a4628cf3887e137843e43c8b22
