x86: i8253: Consolidate definitions of global_clock_event

There are multiple declarations of global_clock_event in header files
specific to particular clock event implementations.  Consolidate them
in <asm/time.h> and make sure all users include that header.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Cc: Venkatesh Pallipadi (Venki) <venki@google.com>
Link: http://lkml.kernel.org/r/20110601180610.762763451@duck.linux-mips.netSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/include/asm/apb_timer.h

@@ -50,7 +50,6 @@
 #define APBT_DEV_USED  1
 
 extern void apbt_time_init(void);
-extern struct clock_event_device *global_clock_event;
 extern unsigned long apbt_quick_calibrate(void);
 extern int arch_setup_apbt_irqs(int irq, int trigger, int mask, int cpu);
 extern void apbt_setup_secondary_clock(void);

arch/x86/include/asm/i8253.h

@@ -3,8 +3,6 @@
 
 #define PIT_LATCH	LATCH
 
-extern struct clock_event_device *global_clock_event;
-
 extern void setup_pit_timer(void);
 
 #endif /* _ASM_X86_I8253_H */

arch/x86/include/asm/time.h

 #ifndef _ASM_X86_TIME_H
 #define _ASM_X86_TIME_H
 
-extern void hpet_time_init(void);
-
+#include <linux/clocksource.h>
 #include <asm/mc146818rtc.h>
 
+extern void hpet_time_init(void);
 extern void time_init(void);
 
+extern struct clock_event_device *global_clock_event;
+
 #endif /* _ASM_X86_TIME_H */

arch/x86/kernel/apb_timer.c

@@ -44,6 +44,7 @@
 #include <asm/fixmap.h>
 #include <asm/apb_timer.h>
 #include <asm/mrst.h>
+#include <asm/time.h>
 
 #define APBT_MASK			CLOCKSOURCE_MASK(32)
 #define APBT_SHIFT			22

arch/x86/kernel/apic/apic.c

@@ -48,6 +48,7 @@
 #include <asm/hpet.h>
 #include <asm/idle.h>
 #include <asm/mtrr.h>
+#include <asm/time.h>
 #include <asm/smp.h>
 #include <asm/mce.h>
 #include <asm/tsc.h>

arch/x86/kernel/hpet.c

@@ -14,6 +14,7 @@
 
 #include <asm/fixmap.h>
 #include <asm/hpet.h>
+#include <asm/time.h>
 
 #define HPET_MASK			CLOCKSOURCE_MASK(32)
 

arch/x86/kernel/i8253.c

@@ -14,6 +14,7 @@
 #include <linux/io.h>
 
 #include <asm/hpet.h>
+#include <asm/time.h>
 #include <asm/smp.h>
 
 /*