ARM: drop <mach/timex.h> for !ARCH_MULTIPLATFORM, too

While <mach/timex.h> isn't used for multi-platform builds since long it
still is for "normal" builds. As the previous patches fix all sites to
not make use of this per-platform file, it can go now for good also for
platforms that are not (yet) converted to multi-platform.

While at it there are no users of CLOCK_TICK_RATE any more, so also drop
the dummy #define.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

arch/arm/mach-exynos/include/mach/timex.h

@@ -1,29 +0,0 @@
-/* linux/arch/arm/mach-exynos4/include/mach/timex.h
- *
- * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
- *		http://www.samsung.com
- *
- * Copyright (c) 2003-2010 Simtec Electronics
- *	Ben Dooks <ben@simtec.co.uk>
- *
- * Based on arch/arm/mach-s5p6442/include/mach/timex.h
- *
- * EXYNOS4 - time parameters
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
-*/
-
-#ifndef __ASM_ARCH_TIMEX_H
-#define __ASM_ARCH_TIMEX_H __FILE__
-
-/* CLOCK_TICK_RATE needs to be evaluatable by the cpp, so making it
- * a variable is useless. It seems as long as we make our timers an
- * exact multiple of HZ, any value that makes a 1->1 correspondence
- * for the time conversion functions to/from jiffies is acceptable.
-*/
-
-#define CLOCK_TICK_RATE 12000000
-
-#endif /* __ASM_ARCH_TIMEX_H */