[llvm] [AArch64] Corrected Latency Descriptions for NeoverseV2 (PR #147339)

[via llvm-commits]

yafet-a wrote:

Confirmed the original N2-writeback.s still passes, meaning the update_mca_test_checks script was only applying formatting changes. The new commit reverts the change to the test and the formatting change has now been left out of this pr since it isnt relevant to the V2 changes.

https://github.com/llvm/llvm-project/pull/147339