[PowerPC] Fix CodeGen/PowerPC/crbit-asm.ll test for -O1

Add the crbits processor feature so that the test can be run at -O1, etc.
regardless of the default crbits setting.

Fixes PR23778.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251548 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed