[AArch64][SVE] Add bfloat16 support to perm and select intrinsics

Summary:
Added for following intrinsics:

  * zip1, zip2, zip1q, zip2q
  * trn1, trn2, trn1q, trn2q
  * uzp1, uzp2, uzp1q, uzp2q
  * splice
  * rev
  * sel

Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D82182