[llvm] [LLVM][ARM] Latency mutations for cortex m55, m7 and m85 (PR #115153)

[Kazu Hirata via llvm-commits]

kazutakahirata wrote:

I'm getting the following warning:

```
llvm/lib/Target/ARM/ARMSubtarget.cpp:255:11: error: enumeration values 'CortexM55' and 'CortexM85' not handled in switch [-Werror,-Wswitch]
  switch (ARMProcFamily) {
          ^~~~~~~~~~~~~
```

Would you mind taking a look?  Thanks!

https://github.com/llvm/llvm-project/pull/115153