[ARM] Add more CPUs to host detection

This returns "cortex-a73" for second-generation Kryo; not precisely
correct, but close enough.

Differential Revision: https://reviews.llvm.org/D37724



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313200 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed