[llvm] [AArch64][SVE] Add dot product lowering for PARTIAL_REDUCE_MLA node (PR #130933)

[Benjamin Maxwell via llvm-commits]

MacDue wrote:

Oh, I think the tests are now failing for when `EnablePartialReduceNodes` is not set (since all types pairs are default to legal in that case). 

https://github.com/llvm/llvm-project/pull/130933