Adding optional CPUID field in microarchitecture schema and in json file for Arm architectures

As part of https://github.com/archspec/archspec/pull/168 on the archspec repo, it was decided to add, where it made sense for ARM cores a new field, called cpuid rather than adding a new submodule just for that.

These changes aim at:

adding the optional field in the microarchitecture_schema file
introducing the field "cpuid" in the ARM microarchitectures

This field will be used in the cpu/detect.py file in the archspec repo, for which a separate PR will be opened.

CC: @dslarm

archspec / archspec-json

Adding optional CPUID field in microarchitecture schema and in json file for Arm architectures #110