[AArch64][SVE] Change pointer type of nontemporal load/store intrinsics

Summary:
This fixes a discrepancy between the non-temporal loads/store
intrinsics and other SVE load intrinsics (such as nf/ff), so
that Clang can use the same code to generate these intrinsics.

Reviewers: andwar, kmclaughlin, rengolin, efriedma

Reviewed By: efriedma

Subscribers: tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76237