AArch64: fix vector-immediate BIC/ORR on big-endian devices.

Follow up to r217138, extending the logic to other NEON-immediate instructions.
As before, the instruction already performs the correct operation and we're
just using a different type for convenience, so we want a true nop-cast.

Patch by Asiri Rathnayake.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217159 91177308-0d34-0410-b5e6-96231b3b80d8