[X86][AVX512] _mm512_stream_load_si512 should take a void const* argument (PR33977)

Based off the Intel Intrinsics guide, we should expect a void const* argument.

Prevents 'passing 'const void *' to parameter of type 'void *' discards qualifiers' warnings.

Differential Revision: https://reviews.llvm.org/D37449

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@312523 91177308-0d34-0410-b5e6-96231b3b80d8