[ARM] CodeGen: Replace AddDefaultT1CC and AddNoT1CC. NFC

For AddDefaultT1CC, we add a new helper t1CondCodeOp, which creates the
appropriate register operand. For AddNoT1CC, we use the existing condCodeOp
helper - we only had two uses of AddNoT1CC, so at this point it's probably not
worth having yet another helper just for them.

Differential Revision: https://reviews.llvm.org/D28603

llvm-svn: 291894