[ARM] Fix MachO CPU Subtype selection

This patch makes the Darwin ARM backend take advantage of TargetParser.  It
also teaches TargetParser about ARMV7K for the first time. This makes target
triple parsing more consistent across llvm.

Differential Revision: http://reviews.llvm.org/D11996


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245081 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed