[LoongArch] Improve pattern matching for AddLike predicate (#82767)

This commit updates the pattern matching logic for the `AddLike`
predicate in `LoongArchInstrInfo.td` to use the
`isBaseWithConstantOffset` function provided by `CurDAG`. This
optimization aims to improve the efficiency of pattern matching by
identifying cases where the operation can be represented as a base
address plus a constant offset, which can lead to more efficient code
generation.