[mips] Kill 'support' for untested EABI.

Summary:
There are no llvm backend tests* for EABI and no EABI buildbots. There were only
three clang tests, all of which checked that -mabi=eabi was passed to the
assembler.

*There is a single backend test that specifies EABI but it actually tests MIPS16.

Reviewers: atanasyan

Subscribers: emaste, sdardis, atanasyan, cfe-commits

Differential Revision: http://reviews.llvm.org/D20679

llvm-svn: 270998
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 39f78c3..33de18d 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1233,7 +1233,7 @@
   if (CPUName.empty()) {
     // Deduce CPU name from ABI name.
     CPUName = llvm::StringSwitch<const char *>(ABIName)
-                  .Cases("o32", "eabi", DefMips32CPU)
+                  .Case("o32", DefMips32CPU)
                   .Cases("n32", "n64", DefMips64CPU)
                   .Default("");
   }