[CodeView] Fix the ARM64 CPUType enum

The old, incorrect one seems to have been added in
d41ac895, with a similarly placed
entry added in EnumTables.cpp in
eb4d6142.

This matches the value documented at
https://docs.microsoft.com/en-us/visualstudio/debugger/debug-interface-access/cv-cpu-type-e?view=vs-2019.

This fixes running obj2yaml on an object file generated by MSVC.

Differential Revision: https://reviews.llvm.org/D100306