AMDGPU: Remove atomic inc/dec patterns

There is no benefit to these since materializing the constant 1
requires the same number of instructions as materializing uint_max

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264215 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed