Hexagon: Delete stale barrier.h

Commit 93ea02bb ("arch: Clean up asm/barrier.h implementations")
wired generic barrier.h for hexagon, but failed to delete the existing
file.

Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Compile-tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/hexagon/include/asm/barrier.h

-/*
- * Memory barrier definitions for the Hexagon architecture
- *
- * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 and
- * only version 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
- */
-
-#ifndef _ASM_BARRIER_H
-#define _ASM_BARRIER_H
-
-#define rmb()				barrier()
-#define read_barrier_depends()		barrier()
-#define wmb()				barrier()
-#define mb()				barrier()
-#define smp_rmb()			barrier()
-#define smp_read_barrier_depends()	barrier()
-#define smp_wmb()			barrier()
-#define smp_mb()			barrier()
-
-/*  Set a value and use a memory barrier.  Used by the scheduler somewhere.  */
-#define set_mb(var, value) \
-	do { var = value; mb(); } while (0)
-
-#endif /* _ASM_BARRIER_H */