ARMSubtarget.h: Change to one line per enum element; NFC

Change syntax to have enum elements sorted alphabetically and one per
line as that is more merge/cherry pick friendly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294677 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed