tile: remove stale arch/tile/kernel/futex_64.S

This should have been removed with commit 47d632f9, but
it was overlooked.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

arch/tile/kernel/futex_64.S

-/*
- * Copyright 2011 Tilera Corporation. 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
- *   as published by the Free Software Foundation, version 2.
- *
- *   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, GOOD TITLE or
- *   NON INFRINGEMENT.  See the GNU General Public License for
- *   more details.
- *
- * Atomically access user memory, but use MMU to avoid propagating
- * kernel exceptions.
- */
-
-#include <linux/linkage.h>
-#include <asm/errno.h>
-#include <asm/futex.h>
-#include <asm/page.h>
-#include <asm/processor.h>
-
-/*
- * Provide a set of atomic memory operations supporting <asm/futex.h>.
- *
- * r0: user address to manipulate
- * r1: new value to write, or for cmpxchg, old value to compare against
- * r2: (cmpxchg only) new value to write
- *
- * Return __get_user struct, r0 with value, r1 with error.
- */
-#define FUTEX_OP(name, ...) \
-STD_ENTRY(futex_##name)			\
-	__VA_ARGS__;			\
-	{				\
-	 move   r1, zero;		\
-	 jrp    lr			\
-	};				\
-	STD_ENDPROC(futex_##name);	\
-	.pushsection __ex_table,"a";	\
-	.quad 1b, get_user_fault;	\
-	.popsection
-
-	.pushsection .fixup,"ax"
-get_user_fault:
-	{ movei r1, -EFAULT; jrp lr }
-	ENDPROC(get_user_fault)
-	.popsection
-
-FUTEX_OP(cmpxchg, mtspr CMPEXCH_VALUE, r1; 1: cmpexch4 r0, r0, r2)
-FUTEX_OP(set, 1: exch4 r0, r0, r1)
-FUTEX_OP(add, 1: fetchadd4 r0, r0, r1)
-FUTEX_OP(or, 1: fetchor4 r0, r0, r1)
-FUTEX_OP(andn, nor r1, r1, zero; 1: fetchand4 r0, r0, r1)