Fix r195149. Triple should correctly reflect that target. If it contains ios,
e.g. thumbv7m-apple-ios3.0.0-eabi, then it should mean it's an iOS target. For
embedded targets, the OS should be unknown, e.g. thumbv7m-apple-unknown-macho.
Since Tim has recently fixed the triple, r195149 is no longer needed.
rdar://15911035


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200164 91177308-0d34-0410-b5e6-96231b3b80d8