Fix confused use of llvm::StringSwitch for armv7r architecture.

svn 170909 added support for cortex-r5 but in this case it was done
incorrectly. The last argument to StringSwitch.Cases() is the replacement
value, so by adding "cortex-r5" it changed the default cpu for armv7r to
cortex-r5 instead of cortex-r4.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176456 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/ToolChain.cpp b/lib/Driver/ToolChain.cpp
index 751c9f8..a7311d7 100644
--- a/lib/Driver/ToolChain.cpp
+++ b/lib/Driver/ToolChain.cpp
@@ -113,7 +113,7 @@
     .Cases("armv7l", "armv7-l", "cortex-a8")
     .Cases("armv7f", "armv7-f", "cortex-a9-mp")
     .Cases("armv7s", "armv7-s", "swift")
-    .Cases("armv7r", "armv7-r", "cortex-r4", "cortex-r5")
+    .Cases("armv7r", "armv7-r", "cortex-r4")
     .Cases("armv7m", "armv7-m", "cortex-m3")
     .Case("ep9312", "ep9312")
     .Case("iwmmxt", "iwmmxt")