[driver][mips] Hardcode triple name in case of CodeSourcery toolchain. NFC
[driver][mips] Hardcode triple name in case of CodeSourcery toolchain. NFC

CodeSourcery toolchain is a standalone toolchain which always uses
the same triple name in its paths. It is independent from target
triple used by the driver.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@270067 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang