[AArch64] Rewrite (add, csel) to cinc

Don't rewrite an add instruction with 2 SET_CC operands into a csel
instruction. The total instruction sequence uses an extra instruction and
register. Preventing this allows us to match a `(add, csel)` pattern and
rewrite this into a `cinc`.

Differential Revision: https://reviews.llvm.org/D98704