[AArch64] Fix creation of invalid instructions with XZR register

A combination of GlobalISel and MachineCombiner can end up creating
`SUB xrz, (MOVI -2105098)` instructions which have not been constant
folded. The AArch64MIPeepholeOpt pass will then attempt to create
`ADD xzr, 513, lsl 12`, which is not a valid instruction. This adds
a bail out of the transform if the register is xzr/wzr.

Fixes #60528

Differential Revision: https://reviews.llvm.org/D143475