Reorder includes in Target backends to following coding standards. Remove some superfluous forward declarations.

llvm-svn: 152997
diff --git a/llvm/lib/Target/Mips/MipsTargetMachine.cpp b/llvm/lib/Target/Mips/MipsTargetMachine.cpp
index 8806aaf..ad02231 100644
--- a/llvm/lib/Target/Mips/MipsTargetMachine.cpp
+++ b/llvm/lib/Target/Mips/MipsTargetMachine.cpp
@@ -11,8 +11,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "Mips.h"
 #include "MipsTargetMachine.h"
+#include "Mips.h"
 #include "llvm/PassManager.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/Support/TargetRegistry.h"