Forgot to remove this file in the last libgo commit.

libgo: remove old MIPS architecture names
    
    This removes the old names for the 3 main MIPS ABIs: mipso32, mipsn32
    and mipsn64. It also removes the mipso64 ABI which has no equivalent
    architecture name in go. This ABI has been dead for sometime and I doubt
    anyone will miss it.
    
    Change-Id: I087b243784edf6705fdaf9c32e3233da5e387283

From-SVN: r249485

libgo/go/internal/syscall/unix/getrandom_linux_mipso32.go

-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build mipso32
-
-package unix
-
-// Linux getrandom system call number.
-// See GetRandom in getrandom_linux.go.
-const randomTrap uintptr = 4353