i8253: Consolidate definitions of PIT_LATCH

x86 defines PIT_LATCH as LATCH which in <linux/timex.h> is defined as
((CLOCK_TICK_RATE + HZ/2) / HZ) and <asm/timex.h> again defines
CLOCK_TICK_RATE as PIT_TICK_RATE.

MIPS defines PIT_LATCH as LATCH which in <linux/timex.h> is defined as
((CLOCK_TICK_RATE + HZ/2) / HZ) and <asm/timex.h> again defines
CLOCK_TICK_RATE as 1193182.

ARM defines PITCH_LATCH as ((PIT_TICK_RATE + HZ / 2) / HZ) - and that's
the sanest thing and equivalent to above definitions so use that as the
new definition in <linux/i8253.h>.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@linux-mips.org
Link: http://lkml.kernel.org/r/20110601180610.832810002@duck.linux-mips.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/arm/include/asm/i8253.h

@@ -1,6 +1,4 @@
 #ifndef __ASMARM_I8253_H
 #define __ASMARM_I8253_H
 
-#define PIT_LATCH	((PIT_TICK_RATE + HZ / 2) / HZ)
-
 #endif

arch/mips/include/asm/i8253.h

@@ -5,8 +5,6 @@
 #ifndef __ASM_I8253_H
 #define __ASM_I8253_H
 
-#define PIT_LATCH		LATCH
-
 extern void setup_pit_timer(void);
 
 #endif /* __ASM_I8253_H */

arch/x86/include/asm/i8253.h

@@ -1,8 +1,6 @@
 #ifndef _ASM_X86_I8253_H
 #define _ASM_X86_I8253_H
 
-#define PIT_LATCH	LATCH
-
 extern void setup_pit_timer(void);
 
 #endif /* _ASM_X86_I8253_H */

include/linux/i8253.h

@@ -9,7 +9,9 @@
 #ifndef __LINUX_I8253_H
 #define __LINUX_I8253_H
 
+#include <linux/param.h>
 #include <linux/spinlock.h>
+#include <linux/timex.h>
 #include <asm/i8253.h>
 
 /* i8253A PIT registers */
@@ -17,6 +19,8 @@
 #define PIT_CH0		0x40
 #define PIT_CH2		0x42
 
+#define PIT_LATCH	((PIT_TICK_RATE + HZ/2) / HZ)
+
 #define inb_pit         inb_p
 #define outb_pit        outb_p