Revert "R600/SI: Fix incorrect encoding of DS_WRITE_B32 instructions"

This reverts commit a6a39ced095c2f453624ce62c4aead25db41a18f.
This is the wrong version of this fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188523 91177308-0d34-0410-b5e6-96231b3b80d8